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Chapter 8:
Organization Leadership
Introduction
Great leaders exist in business, politics, the military, and even
sports
Leadership can be used for good and for evil
Communication is a tool used to activate messages to followers
Leadership is a socially constructed phenomenon
Case Study: Charismatic Preacher
Reverend Jim Jones was a charismatic, influential preacher who
led rapidly growing congregations throughout California
People were so inspired, that they donated their entire worldly
possessions, traveled to South America, and built a community
Several years later, the Reverend leads a mass suicide of 909
people in his town of Jonestown, Guyana
Why would people be so committed to him that they would
participate in a mass suicide?
What does this say about leadership?
Trait Approach to Leadership
If a person has certain traits, they will be a more effective
leader
Big Five personality traits with leadership potential include:
Extraversion
Conscientiousness
Openness to experience
Ambition
Energy
The trait approach to leadership seems to be best able to predict
leader emergence rather than leader effectiveness
There is a difference between possessing a trait and being
perceived to possess a trait
4
Leadership Behaviors
The behavioral approach to leadership examines what leaders
actually do and the behaviors leaders use to achieve their goals
It’s a matter of what you do (behavior theory), rather than who
you are (trait theory) as a leader
Critical Thinking Questions – Traits and Behaviors
How does the perspective that leadership is something you do
versus something you are change the responsibilities of a
leader?
The University of Michigan and Ohio State Studies
Initiating Structure
Extent to which a leader defines and structures the roles of
employees in the goal attainment effort
Production-oriented leaders have behavior similar to initiating
structure
Consideration
Leader respects employees’ thoughts, ideas, and feelings,
expresses appreciation and support, and develops an
environment of mutual trust
Employee-oriented leaders also value consideration
Managerial Grid
Contingent Approaches to Leadership
Questions examined by contingency theorists include:
What are the situational factors that actually matter in
leadership?
To what leadership styles do they best connect?
Least Preferred Co-Worker
Fiedler (1967) developed Least preferred co-worker (LPC)
questionnaire
Rating “least” preferred coworker harshly = task-oriented leader
Rating “least” preferred coworker benevolently = relationship-
oriented
Once individual leadership style is assessed, the situation is
determined through three dimensions: 1) Leader-member
relations 2) Task structure 3) Position power
Critical Thinking Questions – Least Preferred
Why does the way a person treats the least preferred co-worker
likely say the most about their style of leadership?
Think about your experiences working in groups. How did you
feel about the least-preferred group member? What kind of
leader are you likely to be based on this?
Leader-Member Exchange
Leader-Member Exchange Theory demonstrates how leaders can
create their own context, by creating in-groups and out-groups
amongst their own employees
In-Group members receive trust, openness in communication,
and high levels of interactions with the leader
Out-Group members receive less leader attention, more
formalistic relations, and are generally not provided the same
resources and encouragement in their skill development
12
Situational Leadership
Style of leadership should consider the maturity of one’s
subordinates
Model includes four leadership quadrants:
Telling (low maturity employees) to
Selling (low to moderate maturity employees) to
Participating (moderate to high maturity employees) to
Delegating (high maturity employees)
Continuum of Leadership Behavior
Continuum of Leadership Behavior
A successful manager or leader must be able to match his or her
behavior to the specific situation in which they find themselves
From managers making and announcing decisions to…
Subordinates allowed to do so within the limits defined by their
superior
Charismatic Leadership and Transformational Approaches
Attempt to blend three questions into a more unified and
integrated approach:
Is leadership who we are?
Is leadership what we do?
Is leadership the relationship between the leader and situation?
Charismatic Leadership Theory
Asserts that followers attribute extraordinary (even heroic)
leadership abilities to leaders when they observe a certain
combination of leader behaviors, including:
They articulate a vision discrepant from the status quo
They take personal risks to achieve that vision
They demonstrate a sensitivity to followers’ needs
And they exhibit unconventional behavior to galvanize the
attention of employees and demonstrate the leader’s goals and
values
Transformation Leadership Theory
Transactional leaders guide their followers by clarifying role
and task requirements by using:
Laissez Fair leadership
Management by exception leadership
Contingent reward leadership
Transformational leadership builds on this, and inspires
follower effort to transcend their self-interest for the good of
the organization
Individualized consideration, Intellectual stimulation,
Inspirational motivation, Idealized influence
Authentic Leadership
Authentic leadership focuses on the moral aspects of being a
leader, and addresses downfalls of charismatic leadership, that
leaders can be self-interested
Authentic behaviors produce trust, encouraging people have
faith in the leaders who use them
Enhanced trust enhances information sharing, effectiveness, and
productivity
Challenges to the Leadership Construct – Attributions,
Substitutes and Neutralizers
Attribution theory of leadership suggests that leadership is
simply an attribution that people make about other individuals
Further, leader behaviors may not be as relevant in all
organizational situations
There are substitutes and neutralizers that can limit the effects
of leader behavior
For example, leadership may be less effective or needed if
employees are extremely experienced in their jobs, with high
levels of training and ability, are cohesive, and intrinsically
motivated with strong levels of professional orientation. If
employees exhibit individual indifference toward organizational
rewards, or their jobs are highly structured or routinized and
provide their own feedback, the effects of leadership may also
be less significant. Finally, the physical separation of the
leader may have muting effects on leadership.
19
Case Study: Lead with LUV
Colleen Barrett, President of Southwest Airlines, described
leadership in the following way:
“LUV is our symbol on the New York Stock Exchange. We first
started flying out of Love Field in Dallas, and our first
advertising slogan in 1972 was “Southwest Airlines, the
Someone Else Up There Who LUVs You.” We also had a heart
on our first signature line and letterhead. And today, forty years
later, we still have our hearts on our aircraft. So, frankly, if you
have a need to put a label on what I do, I would prefer that you
call me a LUVing Leader.”
Leading Change
A constant in life is that things change, and many people do not
like it
People are uncomfortable with change because of the unknown
Good leaders must be willing to adapt and adjust to change
Good leaders must also try to avoid disasters while managing
change
Vital Aspects of Leading
Being a visionary is one way to be a leader, especially during
times of change
Translating vision into reality requires anchoring,
implementing, and executing a vision
Good leaders also empower others, especially during times of
change
Leadership is about translating intention and vision into reality
Strong communication skills are necessary to be a good leader
Listening, Leadership, and Change
Listening is vital if any leader is going to be truly effective
Especially important during times of change when there is fear
of the unknown
Good leaders understand that listening, even if it means hearing
about our weaknesses, is vital to effective and meaningful
interaction
Leaders should help followers develop into leaders themselves
The Distinction Between Leadership and Management
Leadership and management are not the same
Leadership is the ability to influence a group toward the
achievement of a vision or set of goals
Management is a broader concept that focuses on planning,
organizing, and controlling functions within organizations
Context Matters
For Profit Organizations
Larger corporations tend to have many levels and dimensions of
leadership
Small Businesses
Leadership may be shared and decisions made more quickly
because there are fewer levels
Non-Profit Organizations
Specific values tend to guide and limit leadership
Government Sector
Guided by unique rules that impact leadership decisions
Infrastructure Security
Chapter 10
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Objectives (1 of 2)
Construct networks using different types of network devices.
Enhance security using security devices.
Understand virtualization concepts.
Enhance security using NAC/NAP methodologies.
Identify the different types of media used to carry network
signals.
Describe the different types of storage media used to store
information.
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Objectives (2 of 2)
Use basic terminology associated with network functions related
to information security.
Describe the different types and uses of cloud computing.
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Key Terms (1 of 3)
Basic packet filtering
Bridge
Cloud computing
Coaxial cable
Collision domain
Concentrator
Data loss prevention (DLP)
Firewall
Hypervisor
Hub
Infrastructure as a Service (IaaS)
Internet content filters
Load balancer
Modem
Network access control
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Basic packet filtering – Filtering that looks at each packet
entering or leaving the network and then either accepts the
packet or rejects the packet based on user-defined rules. Each
packet is examined separately.
Bridge – A network device that separates traffic into separate
collision domains at the data layer of the OSI model.
Cloud computing – The automatic provisioning of on demand
computational resources across a network.
Coaxial cable – A network cable that consists of a solid center
core conductor and a physical spacer to the outer conductor
which is wrapped around it. Commonly used in video systems.
Collision domain – An area of shared traffic in a network where
packets from different conversations can collide.
Concentrator – A device used to manage multiple similar
networking operations, such as provide a VPN endpoint for
multiple VPNs.
Data loss prevention (DLP) – Technology, processes, and
procedures designed to detect when unauthorized removal of
data from a system occurs. DLP is typically
active, preventing the loss of data, either by blocking the
transfer or dropping the connection.
Firewall – A network device used to segregate traffic based on
rules.
Hypervisor - A low-level program that allows multiple
operating systems to run concurrently on a single host
computer.
Hub – A network device used to connect devices at the physical
layer of the OSI model.
Infrastructure as a Service (IaaS) – The automatic, on-demand
provisioning of infrastructure elements, operating as a service; a
common element of cloud computing.
Internet content filters – A content-filtering system use to
protect corporations from employees’ viewing of inappropriate
or illegal content at the workplace and the subsequent
complications that occur when such viewing takes place.
Load balancer – A network device that distributes computing
across multiple computers.
Modem – A modulator/demodulator that is designed to connect
machines via telephone-based circuits.
Network access control – An approach to endpoint security that
involves monitoring and remediating endpoint security issues
before allowing an object to connect to a network.
4
Key Terms (2 of 3)
Network Access Protection (NAP)
Network Admission Control (NAC)
Network-Attached Storage (NAS)
Network interface card (NIC)
Network operations center (NOC)
Next-generation firewall
Platform as a Service (PaaS)
Private branch exchange (PBX)
Proxy server
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Network Access Protection (NAP) – A Microsoft approach to
network access control.
Network Admission Control (NAC) – The Cisco technology
approach for generic network access control.
Network-Attached Storage (NAS) – The connection of storage
to a system via a network connection.
Network interface card (NIC) – A piece of hardware designed to
connect machines at the physical layer of the OSI model.
Network operations center (NOC) – A control point from where
network performance can be monitored and managed.
Next-generation firewall – Firewall technology based on packet
contents as opposed to simple address and port information.
Platform as a Service (PaaS) – The concept of having
provisionable operational platforms that can be obtained via a
service.
Private branch exchange (PBX) – A telephone exchange that
serves a specific business or entity.
Proxy server – A server that acts as a proxy for individual
requests and is used for performance and security purposes in a
scalable fashion.
5
Key Terms (3 of 3)
Router
Sandboxing
Servers
Shielded twisted-pair (STP)
Software as a Service (SaaS)
Solid-state drive (SSD)
Switch
Unified threat management (UTM)
Unshielded twisted-pair (UTP)
Virtualization
Web security gateway
Wireless access point
Workstation
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Router – A network device that operates at the network layer of
the OSI model.
Sandboxing – The concept of isolating a system and specific
processes form the OS in order to provide specific levels of
security.
Servers – The computers in a network that host applications and
data for everyone to share.
Shielded twisted-pair (STP) – A physical network connection
consisting of two wires twisted and covered with a shield to
prevent interference.
Software as a Service (SaaS) – The provisioning of software as
a service, commonly known as on-demand software.
Solid-state drive (SSD) – A mass storage device, such as a hard
drive, that is composed of electronic memory as opposed to a
physical device of spinning platters.
Switch – A network device that operates at the data layer of the
OSI model.
Unified threat management (UTM) – The aggregation of
multiple network security products into a single appliance for
efficiency purposes.
Unshielded twisted-pair (UTP) – A form of network cabling in
which pairs of wires are twisted to reduce crosstalk. Commonly
used in LANs.
Virtualization – An abstraction of the OS layer, creating the
ability to host multiple OSs on a single piece of hardware.
Web security gateway – A device that combines proxy functions
with content-filtering functions with the intention of addressing
the security threats and pitfalls unique to web-based traffic.
Wireless access point – A network access device that facilitates
the connection of wireless devices to a network.
Workstation – The machine that sits on the desktop and is used
every day for sending and reading e-mail, creating spreadsheets,
writing reports in a word processing program, and playing
games.
6
Devices
Devices are needed to connect clients and servers and to
regulate the traffic between them.
Devices expand the network beyond simple client computers
and servers.
Devices come in many forms and with many functions.
Each device has a specific network function and plays a role in
maintaining network infrastructure security.
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A complete network computer solution in today’s business
environment consists of more than just client computers and
servers.
Devices are needed to expand a network beyond simple client
computers and servers to include yet other devices, such as
wireless and handheld systems.
Devices come in many forms and with many functions, from
hubs and switches, to routers, wireless access points, and
special-purpose devices such as virtual private network (VPN)
devices.
7
Workstations
The workstation is the machine that sits on the desktop.
It is used every day for sending and reading e-mail, creating
spreadsheets, writing reports in a word processing program, and
playing games.
A workstation connected to a network is an important part of
the network security solution.
Many threats to information security can start at a workstation,
but much can be done in a few simple steps to provide
protection from many of these threats.
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Most users are familiar with the client computers used in the
client/server model called workstation devices.
8
Servers
Servers are the computers in a network that host applications
and data for everyone to share.
Servers come in many sizes.
Server operating systems range from Windows Server, to UNIX,
to Multiple Virtual Storage (MVS) and other mainframe
operating systems
They tend to be more robust than workstation OSs.
They are designed to service multiple users over a network at
the same time.
Servers can host a variety of applications.
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Servers come in many sizes, from small single-CPU boxes that
may be less powerful than a workstation, to multiple-CPU
monsters, up to and including mainframes.
The operating systems used by servers range from Windows
Server, to UNIX, to Multiple Virtual Storage (MVS) and other
mainframe operating systems.
The OS on a server tends to be more robust than the OS on a
workstation system and is designed to service multiple users
over a network at the same time.
Servers can host a variety of applications, including web
servers, databases, e-mail servers, file servers, print servers,
and application servers for middleware applications.
9
Mobile Devices
Mobile devices such as laptops, tablets, and mobile phones are
the latest devices to join the corporate network.
Mobile devices can create a major security gap, as a user may
access separate e-mail accounts, one personal, without antivirus
protection, and the other corporate.
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Device Security, Common Concerns
As more and more interactive devices are being designed, a new
threat source has appeared.
Default accounts and passwords are well known in the hacker
community.
First steps you must take to secure such devices is to change the
default credentials.
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In an attempt to build security into devices, typically, a default
account and password must be entered to enable the user to
access and configure the device remotely. These default
accounts and passwords are well known in the hacker
community, so one of the first steps you must take to secure
such devices is to change the default credentials. Anyone who
has purchased a home office router knows the default
configuration settings and can check to see if another user has
changed theirs. If they have not, this is a huge security hole,
allowing outsiders to “reconfigure” their network devices.
11
Network-Attached Storage
Because of the speed of today’s Ethernet networks, it is possible
to manage data storage across the network.
This has led to a type of storage known as Network- Attached
Storage (NAS).
The combination of inexpensive hard drives, fast networks, and
simple application-based servers has made NAS devices in the
terabyte range affordable for even home users.
As a network device, it is susceptible to attacks.
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Because of the large size of video files, this has become popular
for some users as a method of storing TV and video libraries.
Because NAS is a network device, it is susceptible to various
attacks, including sniffing of credentials and a variety of brute -
force attacks to obtain access to the data.
12
Removable Storage
Removable devices can move data outside of the corporate-
controlled environment.
Removable devices can bring unprotected or corrupted data into
the corporate environment.
All removable devices should be scanned by antivirus software
upon connection to the corporate environment.
Corporate policies should address the copying of data to
removable devices.
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Many mobile devices can be connected via USB to a system and
used to store data—and in some cases vast quantities of data.
This capability can be used to avoid some implementations of
data loss prevention mechanisms.
13
Virtualization (1 of 2)
Virtualization technology is used to allow a computer to have
more than one OS present and, in many cases, operating at the
same time.
Virtualization is an abstraction of the OS layer.
It creates the ability to host multiple OSs on a single piece of
hardware.
A major advantage of virtualization is the separation of the
software and the hardware.
It creates a barrier that can improve many system functions,
including security.
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Virtualization (2 of 2)
The underlying hardware is referred to as the host machine, and
on it is a host OS.
A hypervisor is needed to manage virtual machines (VMs).
Virtual machines are typically referred to as the guest OSs.
Newer OSs are designed to natively incorporate virtualization
hooks.
Common virtualization solutions include:
Microsoft Hyper-V, VMware, Oracle VM VirtualBox, Parallels,
and Citrix Xen
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Exam Tip: A hypervisor is the interface between a virtual
machine and the host machine hardware. Hypervisors are the
layer that enables virtualization.
Either the host OS has built-in hypervisor capability or an
application is needed to provide the hypervisor function to
manage the virtual machines (VMs).
Newer OSs are designed to natively incorporate virtualization
hooks, enabling virtual machines to be employed with greater
ease.
15
Hypervisor (1 of 4)
A hypervisor enables virtualization.
A low-level program that allows multiple operating systems to
run concurrently on a single host computer.
The hypervisor acts as the traffic cop that controls I/O and
memory management.
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Hypervisor (2 of 4)
Major advantages of virtualization:
The separation of the software and the hardware
Creates a barrier that can improve many system functions,
including security.
Either the host OS has built-in hypervisor capability or an
application is needed to provide the hypervisor function to
manage the virtual machines (VMs).
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Hypervisor (3 of 4)
Type 1
Type 1 hypervisors run directly on the system hardware.
Referred to as a native, bare-metal, or embedded hypervisors in
typical vendor literature.
Are designed for speed and efficiency, as they do not have to
operate through another OS layer.
These platforms come with management toolsets to facilitate
VM management in the enterprise.
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Hypervisor (4 of 4)
Type 2
Type 2 hypervisors run on top of a host operating system.
In the beginning, Type 2 hypervisors were the most popular.
Typical Type 2 hypervisors include Oracle’s VirtualBox and
VMware’s VMware Workstation Player.
Are designed for limited numbers of VMs, typically in a
desktop or small server environment.
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Application Cells/Containers
Application cells/containers holds the portions of an OS that it
needs separate from the kernel.
Multiple containers can share an OS and have separate memory,
CPU, and storage threads.
A container consists of an entire runtime environment
The application platform, including its dependencies, is
containerized
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VM Sprawl Avoidance
Sprawl is the uncontrolled spreading of disorganization caused
by a lack of an organizational structure when many similar
elements require management.
VM sprawl is a symptom of a disorganized structure.
VM sprawl avoidance needs to be implemented via policy.
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VM Escape Protection
VM escape occurs when software (typically malware) or an
attacker escapes from one VM to the underlying OS and then
resurfaces in a different VM.
Large-scale VM environments have specific modules designed
to detect escape and provide VM escape protection to other
modules.
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Snapshots
A snapshot is a point-in-time saving of the state of a virtual
machine.
Snapshots uses:
Roll a system back to a previous point in time
Undo operations
Provide a quick means of recovery from a complex, system-
altering change that has gone awry
Snapshots act as a form of backup and are typically much faster
than normal system backup and recovery operations.
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Patch Compatibility
Patches are still needed and should be applied, independent of
the virtualization status.
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Host Availability/Elasticity
In a virtualization environment, protecting the host OS and
hypervisor level is critical for system stability.
Best practice is to avoid the installation of any applications on
the host-level machine.
Elasticity refers to the ability of a system to expand/contract as
system requirements dictate.
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Security Control Testing
It is important to test the controls applied to a system to manage
security operations to ensure that they are providing the desired
results.
It is essential to specifically test all security controls inside the
virtual environment to ensure their behavior is still effective.
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Sandboxing
Sandboxing refers to the quarantine or isolation of a system
from its surroundings.
Virtualization can be used as a form of sandboxing with respect
to an entire system.
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Networking
Networks are used to connect devices together.
Networks are composed of components that perform networking
functions to move data between devices.
Networks begin with network interface cards, then continue in
layers of switches and routers.
Specialized networking devices are used for specific purposes,
such as security and traffic management.
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Network Interface Cards (1 of 2)
To connect a server or workstation to a network, a device
known as a network interface card (NIC) is used.
A NIC is the physical connection between a computer and the
network.
Each NIC port is serialized with a unique code, 48 bits long,
referred to as a Media Access Control address (MAC address).
Unfortunately, these addresses can be changed, or “spoofed,”
rather easily.
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A NIC is a card with a connector port for a particular type of
network connection, either Ethernet or Token Ring. The most
common network type in use for LANs is the Ethernet protocol,
and the most common connector is the RJ-45 connector.
The purpose of a NIC is to provide lower-level protocol
functionality from the OSI (Open System Interconnection)
model. Because the NIC defines the type of physical layer
connection, different NICs are used for different physical
protocols.
NICs come as single-port and multiport, and most workstations
use only a single-port NIC, as only a single network connection
is needed. For servers, multiport NICs are used to increase the
number of network connections, increasing the data throughput
to and from the network.
Each NIC port is serialized with a unique code, 48 bits long,
referred to as a Media Access Control address (MAC address).
These are created by the manufacturer, with 24 bits representing
the manufacturer and 24 bits being a serial number,
guaranteeing uniqueness. MAC addresses are used in the
addressing and delivery of network packets to the correct
machine and in a variety of security situations.
Unfortunately, these addresses can be changed, or “spoofed,”
rather easily. In fact, it is common for personal routers to clone
a MAC address to allow users to use multiple devices over a
network connection that expects a single MAC.
29
Network Interface Cards (2 of 2)
Figure 10.1 Linksys network interface card (NIC)
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This figure shows a common form of a NIC.
30
Hubs
A hub is networking equipment that connects devices that are
using the same protocol at the physical layer of the OSI model.
A hub allows multiple machines in an area to be connected
together in a star configuration with the hub at the center.
All connections on a hub share a single collision domain, a
small cluster in a network where collisions occur.
Increased network traffic can become limited by collisions; this
problem has made hubs obsolete in newer networks.
Hubs also create a security weakness due to sniffing and
eavesdropping issues.
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A hub configuration can save significant amounts of cable and
is an efficient method of configuring an Ethernet backbone.
The collision issue has made hubs obsolete in newer, higher
performance networks, with inexpensive switches and switched
Ethernet keeping costs low and usable bandwidth high. Hubs
also create a security weakness in that all connected devices see
all traffic, enabling sniffing and eavesdropping to occur. In
today’s networks, hubs have all but disappeared, being replaced
by low-cost switches.
31
Bridges
A bridge operates at the data link layer, filtering traffic based
on MAC addresses.
Bridges can reduce collisions by separating pieces of a network
into two separate collision domains.
This only cuts the collision problem in half.
A better solution is to use switches for network connections.
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Bridges are networking equipment that connect devices using
the same protocol at the data link layer of the OSI model.
32
Switches (1 of 4)
A switch forms the basis for connections in most Ethernet-based
LANs.
Switches have replaced hubs and bridges.
A switch has separate collision domains for each port.
When full duplex is employed, collisions are virtually
eliminated from the two nodes, host and client.
A switch is usually a Layer 2 device, but Layer 3 switches
incorporate routing functionality.
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A switch has separate collision domains for each port. This
means that for each port, two collision domains exist: one from
the port to the client on the downstream side, and one from the
switch to the network upstream. When full duplex is employed,
collisions are virtually eliminated from the two nodes, host and
client. This also acts as a hub-based system, where a single
sniffer can see all of the traffic to and from connected devices.
Switches operate at the data link layer, while routers act at the
network layer. For intranets, switches have become what routers
are on the Internet—the device of choice for connecting
machines. As switches have become the primary network
connectivity device, additional functionality has been added to
them. A switch is usually a Layer 2 device, but Layer 3
switches incorporate routing functionality.
33
Switches (2 of 4)
Advantages of switches
They improve network performance by filtering traffic.
They provide the option to disable a port so that it cannot be
used without authorization.
They support port security allowing the administrator to control
which systems can send data to each of the ports.
Switches use the MAC address of the systems to incorporate
traffic filtering and port security features.
Port address security based on MAC addresses functionality is
what allows an 802.1X device to act as an “edge device.”
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A switch filters traffic by only sending the data to the port on
the switch that the destination system resides on. The switch
knows what port each system is connected to and sends the data
only to that port.
The switch uses the MAC address of the systems to incorporate
traffic filtering and port security features, which is why it is
considered a Layer 2 device.
Port address security based on MAC addresses can determine
whether a packet is allowed or blocked from a connection. This
is the very function that a firewall uses for its determination,
and this same functionality is what allows an 802.1X device to
act as an “edge device.”
34
Switches (3 of 4)
Switch security concerns
They are intelligent network devices and are therefore subject to
hijacking by hackers.
Switches are commonly administered using the Simple Network
Management Protocol (SNMP) and Telnet protocol.
Both protocols have a serious weakness in that they send
passwords across the network in cleartext.
Switches are shipped with default passwords.
Switches are subject to electronic attacks, such as ARP
poisoning and MAC flooding.
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One of the security concerns with switches is that, like routers,
they are intelligent network devices and are therefore subject to
hijacking by hackers. Should a hacker break into a switch and
change its parameters, he might be able to eavesdrop on specific
or all communications, virtually undetected. Switches are
commonly administered using the Simple Network Management
Protocol (SNMP) and Telnet protocol, both of which have a
serious weakness in that they send passwords across the
network in cleartext. A hacker armed with a sniffer that
observes maintenance on a switch can capture the administrative
password. This allows the hacker to come back to the switch
later and configure it as an administrator. An additional
problem is that switches are shipped with default passwords,
and if these are not changed when the switch is set up, they
offer an unlocked door to a hacker.
Switches are also subject to electronic attacks, such as ARP
poisoning and MAC flooding. ARP poisoning is where a device
spoofs the MAC address of another device, attempting to change
the ARP tables through spoofed traffic and the ARP table-
update mechanism. MAC flooding is where a switch is
bombarded with packets from different MAC addresses,
flooding the switch table and forcing the device to respond by
opening all ports and acting as a hub. This enables devices on
other segments to sniff traffic.
35
Switches (4 of 4)
Loop protection is a concern with switches.
Switches operate at Layer 2 so there is no countdown
mechanism to kill packets that get caught in loops or on paths
that will never resolve.
The Layer 2 space acts as a mesh, where potentially the addition
of a new device can create loops in the existing device
interconnections.
Spanning trees technology is employed to prevent loops.
The Spanning Tree Protocol (STP) allows for multiple,
redundant paths, while breaking loops to ensure a proper
broadcast pattern.
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Routers (1 of 2)
A router is a network traffic management device used to connect
different network segments.
Operate at the network layer (Layer 3) of the OSI model
Form the backbone of the Internet
Use algorithms and tables to determine where to send the packet
Use access control lists (ACLs) as a method of deciding whether
a packet is allowed to enter the network
Must limit router access and control of internal functions
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Routers operate at the network layer (Layer 3) of the OSI …
Network Fundamentals
Chapter 9
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Objectives
Identify the basic network architectures.
Define the basic network protocols.
Explain routing and address translation.
Classify security zones.
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Key Terms (1 of 3)
Address Resolution Protocol (ARP)
Bus topology
Datagram
Denial-of-service (DoS)
Domain Name System (DNS)
DMZ
Dynamic Host Configuration Protocol (DHCP)
Enclave
Ethernet
Extranet
Flat network
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Address Resolution Protocol (ARP) – A protocol in the TCP/IP
suite specification used to map an IP address to a Media Access
Control (MAC) address.
Bus topology – A network layout in which a common line (the
bus) connects devices.
Datagram – A packet of data that can be transmitted over a
packet-switched system in a connectionless mode.
Denial-of-service (DoS) – An attack in which actions are taken
to deprive authorized individuals from accessing a system, its
resources, the data it stores or processes, or the network to
which it is connected.
Domain Name System (DNS) – An attack in which actions are
taken to deprive authorized individuals from accessing a
system, its resources, the data it stores or processes, or the
network to which it is connected.
DMZ – A network segment that exists in a semi-protected zone
between the Internet and the inner, secure trusted network.
Dynamic Host Configuration Protocol (DHCP) – An Internet
Engineering Task Force (IETF) Internet Protocol (IP)
specification for automatically allocating IP addresses and other
configuration information based on network adapter addresses.
It enables address pooling and allocation and simplifies TCP/IP
installation and administration.
Enclave – A section of a network that serves a specific purpose
and is isolated by protocols from other parts of a network.
Ethernet – The common name for the IEEE 802.3 standard
method of packet communication between two nodes at layer 2.
Extranet – an extension of a selected portion of a company’s
intranet to external partners.
Flat network – A network design that avoids packet-looping
issues through an architecture that does not have tiers.
3
Key Terms (2 of 3)
Internet Control Message Protocol (ICMP)
Internet Protocol (IP)
Intranet
Local area network (LAN)
Media Access Control (MAC) address
Mixed topology
Network
Network Address Translation (NAT)
Packet
Protocol
Ring topology
Routing
Star topology
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Internet Control Message Protocol (ICMP) – One of the core
protocols of the TCP/IP protocol suite, used for error reporting
and status messages.
Internet Protocol (IP) – The network layer protocol used by the
Internet for routing packets across a network.
Intranet – a private, internal network that uses common network
technologies (such as HTTP, FTP, and so on) to share
information and provide
resources to organizational users.
Local area network (LAN) – A grouping of computers in a
network structure confined to a limited area and using specific
protocols, such as Ethernet for OSI Layer 2 traffic addressing.
Media Access Control (MAC) address – The data link layer
address for local network addressing.
Mixed topology - Larger networks, such as those inside an
office complex, may use more than one topology at the same
time.
Network – A means to connect two or more computers together
for the purposes of sharing network information.
Network Address Translation (NAT) – A method of
readdressing packets in a network at a gateway point to enable
the use of local nonroutable IP addresses over a public network
such as the Internet.
Packet – Smaller pieces of data used for transmission resulting
from the breaking up of larger data.
Protocol – An agreed-upon format for exchanging or
transmitting data between systems, enable computers to
communicate.
Ring topology – A network layout in which network components
are connected to each other in a closed loop with each device
directly connected to two other devices.
Routing – That process of moving packets from one network to
another.
Star topology – A network topology where network components
are connected to a central point.
4
Key Terms (3 of 3)
Storage area network (SAN)
Subnet mask
Subnetting
Three-way handshake
Topology
Transmission Control Protocol (TCP)
Trunking
Tunneling
User Datagram Protocol (UDP)
Virtual local area network (VLAN)
Wide area network (WAN)
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Storage area network (SAN) – A technology-based storage
solution consisting of network attached storage.
Subnetting – The creation of a network within a network by
manipulating how an IP address is split into network and host
portions.
Subnet mask – The information that tells a device how to
interpret the network and host portions of an IP address.
Three-way handshake – A means of ensuring information
transference through a three-step data exchange. Used to initiate
a TCP connection.
Topology – Describes how the network is physically or
logically arranged.
Transmission Control Protocol (TCP) – The connection-oriented
transport layer protocol for use on the Internet that allows
packet-level tracking of a conversation.
Trunking – The process of spanning a single VLAN across
multiple switches.
Tunneling – The process of packaging packets so that they can
traverse a network in a secure, confidential manner.
User Datagram Protocol (UDP) – A protocol in the TCP/ IP
protocol suite for the transport layer that does not sequence
packets—it is “fire and forget” in nature.
Virtual local area network (VLAN) – A broadcast domain inside
a switched system.
Wide area network (WAN) – A network that spans a large
geographic region.
5
Introduction
By the simplest definition in the data world, a network is a
means to connect two or more computers together for the
purposes of sharing information.
The term “network” has different meanings depending on the
context and usage.
Though data networks vary widely in size and scope, they are
generally defined in terms of their architecture, topology, and
protocol.
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Network sizes and shapes vary drastically—from two personal
computers connected with a crossover cable or wireless router
to the Internet, encircling the globe and linking together untold
numbers of individual, distributed systems.
6
Network Architectures (1 of 3)
A local area network (LAN) typically is smaller in terms of size
and geographic coverage and consists of two or more connected
devices.
Home networks and most small office networks can be
classified as LANs.
A wide area network (WAN) tends to be larger, covering more
geographic area, and consists of two or more systems in
geographically separated areas.
They are connected by leased lines, radio waves, satellite
relays, microwaves, or even dial-up connections.
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Exam Tip: A LAN is a local area network—an office building,
home network, and so on. A WAN is a wide area network—a
corporate network connecting offices in Dallas, New York, and
San Jose, for example.
Every network has an architecture—whether by design or by
accident. Defining or describing a specific network’s
architecture involves identifying the network’s physical
configuration, logical operation, structure, procedures, data
formats, protocols, and other components. For the sake of
simplicity and categorization, people tend to divide network
architectures into two main categories: LANs and WANs.
7
Network Architectures (2 of 3)
Figure 9.1 Corporate WAN connecting multiple offices
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Most corporations have multiple LANs within each office
location that all connect to a WAN that provides intercompany
connectivity.
This figure shows an example of a corporate network. Each
office location will typically have one or more LANs, which are
connected to the other offices and the company headquarters
through a corporate WAN.
8
Network Architectures (3 of 3)
Specialized network structures are classified by size and use.
Campus area network (CAN)
Intranet
Internet
Metropolitan area network (MAN)
Storage area network (SAN)
Virtual local area network (VLAN)
Client/server
Peer-to-peer
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Over time, as networks have grown, diversified, and multiplied,
the line between LAN and WAN has become blurred. To better
describe emerging, specialized network structures, new terms
have been coined to classify networks based on size and use:
Campus area network (CAN) – A network connecting any
number of buildings in an office or university complex (also
referred to as a campus wide area network).
Intranet – A “private” network that is accessible only to
authorized users. Many large corporations host an intranet to
facilitate information sharing within their organization.
Internet – The “global network” connecting hundreds of
millions of systems and users.
Metropolitan area network (MAN) – A network designed for a
specific geographic locality such as a town or a city.
Storage area network (SAN) – A high-speed network connecting
a variety of storage devices such as tape systems, RAID arrays,
optical drives, file servers, and others.
Virtual local area network (VLAN) – A logical network
allowing systems on different physical networks to interact as if
they were connected to the same physical network.
Client/server – A network in which powerful, dedicated systems
called servers provide resources to individual workstations or
clients.
Peer-to-peer – A network in which every system is treated as an
equal, such as a home network.
9
Network Topology (1 of 5)
Topology refers to how the network is physically or logically
arranged.
The main classes of network topologies are:
Star topology – components connected to a central point
Bus topology – components connected to the same cable, often
called “the bus” or “the backbone”
Ring topology – components connected to each other in a closed
loop with each device directly connected to two other devices
Mixed topology – uses more than one topology
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Network Topology (2 of 5)
Figure 9.2 Star topology
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Network Topology (3 of 5)
Figure 9.3 Bus topology
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Network Topology (4 of 5)
Figure 9.4 Ring topology
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Network Topology (5 of 5)
Figure 9.5 Mixed topology
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Larger networks, such as those inside an office complex, may
use more than one topology at the same time. For example, an
office complex may have a large ring topology that
interconnects all the buildings in the complex. Each building
may have a large bus topology to interconne ct star topologies
located on each floor of the building. This is called a mixed
topology or hybrid topology.
14
Wireless
Wireless networking is the transmission of packetized data by
means of a physical topology that does not use direct physical
links.
Hub-and-spoke: wireless access point is the hub and is
connected to the wired network
Mesh: wireless units talk directly to each other, without a
central access point
Ad-Hoc: systems on the network direct packets to and from
their source and target locations without using a central router
or switch
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Network Protocols
When engineers first started to connect computers together via
networks, they quickly realized they needed a commonly
accepted method for communicating—a protocol.
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Protocols (1 of 4)
A protocol is an agreed-upon format for exchanging or
transmitting data between systems.
A protocol defines a number of agreed-upon parameters, such as
the data compression method, the type of error checking to use,
and mechanisms for systems to signal when they have finished
either receiving or transmitting data.
Most networks are dominated by Ethernet and Internet Protocol.
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Protocols (2 of 4)
AppleTalk
Asynchronous Transfer Mode (ATM)
Ethernet
Fiber Distributed Data Interface (FDDI)
Internet Protocol (IP)
Internetwork Packet Exchange (IPX)
Signaling System 7 (SS7)
Systems Network Architecture (SNA)
Token Ring
Transmission Control Protocol/Internet Protocol (TCP/IP)
X.25A protocol
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There is a wide variety of protocols, each designed with certain
benefits and uses in mind. Some of the more common protocols
that have been used in networking are:
AppleTalk – The communications protocol developed by Apple
to connect Macintosh computers and printers.
Asynchronous Transfer Mode (ATM) – A protocol based on
transferring data in fixed-size packets. The fixed packet sizes
help ensure that no single data type monopolizes the available
bandwidth.
Ethernet – The LAN protocol developed jointly by Xerox, DEC,
and Intel—the most widely implemented LAN standard.
Fiber Distributed Data Interface (FDDI) – The protocol for
sending digital data over fiber-optic cabling.
Internet Protocol (IP) – The protocols for managing and
transmitting data between packet-switched computer networks,
originally developed for the Department of Defense. Most users
are familiar with Internet protocols such as e-mail, File Transfer
Protocol (FTP), Telnet, and Hypertext Transfer Protocol
(HTTP).
Internetwork Packet Exchange (IPX) – The networking protocol
created by Novell for use with Novell NetWare operating
systems.
Signaling System 7 (SS7) – The telecommunications protocol
used between private branch exchanges (PBXs) to handle tasks
such as call setup, routing, and teardown.
Systems Network Architecture (SNA) – A set of network
protocols developed by IBM, originally used to connect IBM’s
mainframe systems.
Token Ring – A LAN protocol developed by IBM that requires
systems to possess the network “token” before transmitting
data.
Transmission Control Protocol/Internet Protocol (TCP/IP) – The
collection of communications protocols used to connect hosts on
the Internet. TCP/IP is by far the most commonly used network
protocol and is a combination of the TCP and IP protocols.
X.25A protocol – Developed by the Comité Consultatif
International Téléphonique et Télégraphique (CCITT) for use in
packet-switched networks. The CCITT was a subgroup within
the International Telecommunication Union (ITU) before the
CCITT was disbanded in 1992.
18
Protocols (3 of 4)
In most cases, communications protocols were developed
around the Open System Interconnection (OSI) model.
OSI defines a framework for implementing protocols and
networking components in seven distinct layers.
Control is passed from one layer to another (top-down) before it
exits one system and enters another system, where control is
passed bottom-up to complete the communications cycle.
Most protocols only loosely follow the OSI model.
Several protocols combine one or more layers.
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The OSI model, or OSI Reference Model, is an International
Organization for Standardization (ISO) standard for worldwide
communications that defines a framework for implementing
protocols and networking components in seven distinct layers.
The OSI model also provides a certain level of abstraction and
isolation for each layer, which only needs to know how to
interact with the layer above and below it. The application
layer, for example, only needs to know how to communicate
with the presentation layer—it does not need to talk directly to
the physical layer.
19
Protocols (4 of 4)
Figure 9.6 The OSI Reference Model
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This figure shows the different layers of the OSI model.
20
Packets (1 of 4)
Large chunks of data must typically be broken up into smaller,
more manageable chunks before they are transmitted from one
computer to another.
Advantages of breaking the data up include:
More effective sharing of bandwidth with other systems
Not needing to retransmit the entire dataset if there is a problem
in transmission
When data is broken up into smaller pieces for transmission,
each of the smaller pieces is typically called a packet.
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Networks are built to share information and resources, but like
other forms of communication, networks and the protocols they
use have limits and rules that must be followed for effective
communication.
Each protocol has its own definition of a packet—dictating how
much data can be carried, what information is stored where,
how the packet should be interpreted by another system, and so
on.
A standard packet structure is a crucial element in a protocol
definition. Without a standard packet structure, systems would
not be able to interpret the information coming to them from
other systems. Packet-based communication systems have other
unique characteristics, such as size, which need to be addressed.
This is done via a defined maximum and fragmenting packets
that are too big.
21
Packets (2 of 4)
Maximum Transmission Unit (MTU) is a factor in determining
the number of packets into which a message must be broken.
It represents the largest packet that can be carried across a
network channel.
The value of the MTU is used by TCP to prevent packet
fragmentation at intervening devices.
Packet fragmentation is the splitting of a packet while in transit
into two packets so that they fit past an MTU bottleneck.
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When transmitting packets across a network, there are many
intervening protocols and pieces of equipment, each w ith its
own set of limitations.
22
Packets (3 of 4)
Packet fragmentation is a method of handling large packets.
Internet Protocol has a mechanism for the handling of packets
that are larger than allowed across a hop.
Under ICMP v4, a router has two options:
Break the packet into two fragments, sending each separately
Drop the packet and send an ICMP message back to the
originator, indicating that the packet is too big
The fragmentation problem can cause excessive levels of packet
retransmission.
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Built into the Internet Protocol is a mechanism for handling of
packets that are larger than allowed across a hop. Under ICMP
v4, a router has two options when it encounters a packet that is
too large for the next hop: break the packet into two fragments,
sending each separately, or drop the packet and send an ICMP
message back to the originator, indicating that the packet is too
big. When a fragmented packet arrives at the receiving host, it
must be reunited with the other packet fragments and
reassembled. One of the problems with fragmentation is that it
can cause excessive levels of packet retransmission as TCP
must retransmit an entire packet for the loss of a single
fragment. In IPv6, to avoid fragmentation, hosts are required to
determine the minimal path MTU before transmission of packets
to avoid fragmentation en route. Any fragmentation
requirements in IPv6 are resolved at the origin, and if
fragmentation is required, it occurs before sending.
23
Packets (4 of 4)
Steps are taken to avoid fragmentation in IPv6.
Hosts are required to determine the minimal path MTU before
transmission of packets to avoid fragmentation en route.
Any fragmentation requirements in IPv6 are resolved at the
origin, and if fragmentation is required, it occurs before
sending.
IP fragmentation can be exploited in a variety of ways to bypass
security measures.
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IP fragmentation can be exploited in a variety of ways to bypass
security measures. Packets can be purposefully constructed to
split exploit code into multiple fragments to avoid IDS
detection. Because the reassembly of fragments is dependent
upon data in the fragments, it is possible to manipulate the
fragments to result in datagrams that exceed the 64KB limit,
resulting in denial of service.
24
Internet Protocol (1 of 2)
The Internet Protocol (IP) is not a single protocol but a suite of
protocols.
The two versions of the protocol in use are v4 and v6.
There are differences between the two versions.
One difference is the replacement of the Internet Group
Management Protocol (IGMP) with the Internet Control
Message Protocol (ICMP) and Multicast Listener Discovery
(MLD) in IPv6
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Internet Protocol (2 of 2)
Figure 9.7 Internet Protocol suite components
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This figure shows the relationship between some of the IP suite
and the OSI model.
26
IP Packets (1 of 2)
An IP packet, often called a datagram, has two main sections:
Header – contains all of the information needed to describe the
packet.
Data section – sometimes called the payload
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IP Packets (2 of 2)
Figure 9.8 Logical layout of an IP packet, (a) IPv4 (b) IPv6
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In IPv6, the source and destination addresses take up much
greater room, and for equipment and packet handling reasons,
most of the informational options have been moved to the
optional area after the addresses. This series of optional
extension headers allows the efficient use of the header in
processing the routing information during packet routing
operations. One of the most common options is the IPsec
extension, which is used to establish IPsec connections. IPsec
uses encryption to provide a variety of protections to packets.
28
TCP vs. UDP (1 of 4)
Two protocols required for Internet’s existence
Transmission Control Protocol (TCP) and User Datagram
Protocol (UDP)
Both protocols run on top of the IP network protocol.
As separate protocols, they each have their own packet
definitions, capabilities, and advantages.
Most important difference between TCP and UDP is the concept
of “guaranteed” reliability and delivery.
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Exam Tip: TCP is a “connection-oriented” protocol and offers
reliability and guaranteed delivery of packets. UDP is a
“connectionless” protocol with no guarantees of delivery.
29
TCP vs. UDP (2 of 4)
UDP is known as a “connectionless” protocol.
It has very few error recovery services and no guarantee of
packet delivery.
Sender has no idea whether the packets were successfully
received or whether they were received in order.
UDP is considered to be an unreliable protocol.
UDP is good for time synchronization requests, name lookups,
and streaming audio.
It is a fairly “efficient” protocol in terms of content delivery
versus overhead.
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With UDP, more time and space is dedicated to content (data)
delivery than with other protocols such as TCP. This makes
UDP a good candidate for streaming protocols, as more of the
available bandwidth and resources are used for data delivery
than with other protocols.
30
TCP vs. UDP (3 of 4)
TCP is a “connection-oriented” protocol specifically designed
to provide a reliable connection between two hosts exchanging
data.
TCP is designed to ensure packets processed in the same order
in which they were sent.
Packet sequence number shows where each packet fits into the
overall conversation.
TCP requires systems to follow a specific pattern when
establishing communications called the three-way handshake.
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As part of TCP, each packet has a sequence number to show
where that packet fits into the overall conversation. With the
sequence numbers, packets can arrive in any order and at
different times and the receiving system will still know the
correct order for processing them. The sequence numbers also
let the receiving system know if packets are missing—receiving
packets 1, 2, 4, and 7 tells us that packets 3, 5, and 6 are
missing and needed as part of this conversation. The receiving
system can then request retransmission of packets from the
sender to fill in any gaps.
The “guaranteed and reliable” aspect of TCP makes it very
popular for many network applications and services such as
HTTP, FTP, and Telnet.
31
TCP vs. UDP (4 of 4)
Figure 9.9 TCP’s three-way handshake
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As part of the connection, TCP requires that systems follow a
specific pattern when establishing communications. This
pattern, often called the three-way handshake, is a sequence of
very specific steps:
The originating host (usually called the client) sends a SYN
(synchronize) packet to the destination host (usually called the
server). The SYN packet tells the server what port the client
wants to connect to and the initial packet sequence number of
the client.
The server sends a SYN/ACK packet back to the client. This
SYN/ACK (synchronize/acknowledge) tells the client “I
received your request” and also contains the server’s initial
packet sequence number.
The client responds to the server with an ACK packet to
complete the connection establishment process.
Note: Think of the three-way handshake as being similar to a
phone call. You place a call to your friend—that’s the SYN.
Your friend answers the phone and says “hello”—that’s the
SYN/ACK. Then you say “Hi, it’s me”—that’s the ACK. Your
connection is established and you can start your conversation.
32
ICMP (1 of 2)
Internet Control Message Protocol (ICMP) is probably the third
most commonly used protocol.
ICMP is a control and information protocol.
It is used by network devices to determine such things as a
remote network’s availability, the length of time to reach a
remote network, and the best route for packets to take when
traveling to that remote network.
ICMP can also be used to handle traffic flow.
ICMP is a connectionless protocol designed to carry small
messages quickly with minimal overhead or impact to
bandwidth.
Principles of Computer Security, Fifth Edition
Copyright © 2018 by McGraw-Hill Education. All rights
reserved.
During the early development of large networks, it was quickly
discovered that there needed to be some mechanism for
managing the overall infrastructure —handling connection
status, traffic flow, availability, and errors. This mechanism is
ICMP.
ICMP can also be used to handle the flow of traffic, telling
other network devices to “slow down” transmission speeds if
packets are coming in too fast. ICMP, like UDP, is a
connectionless protocol. ICMP was designed to carry small
messages quickly with minimal overhead or impact to
bandwidth.
33
ICMP (2 of 2)
ICMP has been greatly abused …
Chapter 12:
Celebrating Diversity
Introduction
The landscape of the workplace has changed
As the United States becomes more diverse, markets, customers,
and employees become more diverse
Changes in the racial and ethnic makeups of the work
environment are significant
By 2060 white Americans will only make up 43% of the U.S.
population
Women are expected to represent the majority of the U.S.
workforce by 2020
Case Study: Bass Pro Shop
In the mid-2000s, managers at various Bass Pro Shops stores
using discriminatory language and hiring practices were
reported
A lawsuit was filed against the corporation and is still being
litigated today
What terms make you feel uncomfortable?
Does it surprise you that there are still situations like this
today?
Is this an isolated case?
Major Diversity Categories in Organizations
Race: Percentage of traditional racial minorities in the U.S.
workforce is increasing
National origin: Growing proportion of today’s workers are
immigrants, and English is not their first language
Age: Increasing number of employees expect to work past the
traditional retirement age
Disability: Firms need to provide reasonable accommodation so
workplaces are accessible
Religion: Inclusion of diverse religious faiths and customs
Sex: Ensure equal access and opportunities in hiring
Engaging a Diverse Environment
The number of women and people of color in the American
workforce is increasing
The average age of the American workforce is increasing
Diversity encompasses how we think, act, conduct business;
more than just what we “look like”
The Aging Workforce
Between 1977 and 2007, employment of workers 65+ increased
101%, compared to a much smaller increase of 59% for total
employment
With the aging of the baby-boom generation, the older age
cohorts are expected to make up a larger proportion of the labor
force in the next two decades
This aging workforce impacts the organizational environment in
many ways, including stereotypes
Organizations are stronger when workers embrace the
differences in understandings, experiences, attitudes, and
expectations that each generation has to offer
Sex and Gender Issues
Number of men in the workforce increased by about 53% from
1967-2009
During the same timespan, the number of women in the
workforce increased by over 190%
Incomes for women in the workforce are rising, but there is still
a significant gap between earnings of men and women
Institutionalization of masculine male and feminine female
complicates understanding
It is important to distinguish between sex and gender
Critical Thinking Questions – Sex and Gender
Why do sex and gender matter in organizational
communication?
In what ways is masculinity celebrated and/or dismissed in our
culture? In the workplace?
In what ways is femininity celebrated and/or dismissed in our
culture? In the workplace?
Racial and Ethnic Issues
Higher population growth and increasing participation rates
mean minorities in the workforce will increase significantly
Discrimination still remains a problem
A healthy work environment will develop an understanding and
climate that sees all individuals as people of equal worth
Disabled Workers
American with Disabilities Act (ADA) passed into law in 1990,
prohibiting discrimination against individuals with disabilities
in all areas of public life
Employers must provide reasonable accommodation for disabled
employees
If a disability is not job-related or can be accommodated,
organizations should not discriminate
Communication technology is providing additional
opportunities that influence the ability of the disabled worker
Intercultural Issues
Culture: system of shared values, beliefs, and meaning
Ethnocentrism: evaluating others’ culture against our own
Perception: influences our worldview
Stereotyping: judging a person based on the group to which we
perceive them as belonging
Nonverbal differences: meaning of a symbol in one country may
differ in another; a potential barrier
Language difference: can even vary between regions
Cultural intelligence: adapting, selecting, shaping cultural
aspects of environment
Critical Thinking Questions - Diversity
In what ways have you been discriminated against because of
your:
Age?
Race?
Sex or gender?
Abilities?
What are some of the issues or barriers that prevent us from
communicating effectively in intercultural environments?
Dealing with Emotion
Emotions are intense feelings directed at someone or something
Both energy and stability are needed in the workplace
Just like personality, a range (or diversity) of emotional
response when balanced can help keep an organizational team
focused and effective
Emotions can help us gauge the effectiveness of potential
changes, response to decisions, or buy-in to future projects
Understanding Personality
Personality describes the sum total of ways in which an
individual reacts to and interacts with others
One personality type is not better than another – they are just
different
We must be aware of our own personality and the impact it has
on our environment – and make adjustments when necessary
Discrimination
Stereotypes often lead to workplace discrimination
Whether an individual is a person of color or white, male or
female, gay or straight, disabled or otherly abled are often
extraneous factors not relevant to the organizational or job-
related decision at hand
When we place individuals or groups of people in categories,
we rob them of their uniqueness and individuality
Sexual Harassment
Sexual harassment is a special abuse of power that we discuss
briefly here because it becomes a hindrance to diversity
Unwanted sexual advances, requests for sexual favors, and other
verbal or physical conduct of a sexual nature that create a
hostile or offensive work environment
Organizations must train and educate their employees on what
sexual harassment is, and what policies and practices exist
within the organization and the law to guard against sexual
harassment
Technology and Diversity
Technology can both encourage and hinder diversity
Technology can also provide more tools to manage the process
to improve communication and a different method of dealing
with cross-cultural communication issues and stereotypes
A text-only (email or texting)
Voice-only (traditional phone)
Using a more rich channel of verbal and non-verbal information
(voice and physical)
Face-to-face or video-conference
Organizational Culture and Diversity
Organizational Values
Organizational values should primarily align with personal
values if one is to feel comfortable participating in the
organizational environment
An appreciation for diversity is vital for organizational success
A diversity of ideas and values in regards to the direction and
movement of the organization helps leaders make better
decisions
Leadership and Management Styles
Different organizational environments require different types of
leadership
Even in the same organization, different styles and approaches
are necessary with different employees or in different situations
Diversity in leadership and management styles is important for
organizational success
Climate Issues
Organizational climate is the shared perception of employees of
the properties of the work environment that guide expected
behavior
Safety, justice, clarity of rules and regulations, as well as clear
goals and expectations, help employees understand how they
and others fit into the organization
It is important for a diverse organization to emphasize the need
for a variety of ideas, with standards of performance and
expectations of teamwork and encouraging a variety of inputs
from diverse sources
Working with Difficult People
In a diverse work environment, there’s an enhanced likelihood
that we are going to work with someone who sees things from a
different point of view
This is a core benefit of diversity; it is also a personal
challenge, as you may have to accomplish tasks with people
who you do not understand or agree with
Practice the art of active listening, whereby you truly listen to
another’s point of view
Effective Organizational Diversity Programs
Firms can focus on attracting diverse applicants by targeting
recruiting messages to specific demographic groups currentl y
underrepresented in one’s workforce
An effective diversity program will also educate managers about
the legal framework of equal employment opportunity,
encourage equitable treatment of all employees regardless of
diversity characteristics
Firms can foster practices that focus on bringing out the full
potential of the diversity in their organizations
Context Matters
For-Profit Organization
Good-ole-boy networks can make it difficult for large
organizations to embrace diversity
Entrepreneurship
Families and small businesses often do not have enough
employees to truly encourage diversity
Nonprofit Organization
Focus of the company may influence consideration of diversity
Government Sector
Differing political views influence government policies

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Chapter 8 Organization LeadershipIntroductionGreat le

  • 1. Chapter 8: Organization Leadership Introduction Great leaders exist in business, politics, the military, and even sports Leadership can be used for good and for evil Communication is a tool used to activate messages to followers Leadership is a socially constructed phenomenon Case Study: Charismatic Preacher Reverend Jim Jones was a charismatic, influential preacher who led rapidly growing congregations throughout California People were so inspired, that they donated their entire worldly possessions, traveled to South America, and built a community Several years later, the Reverend leads a mass suicide of 909 people in his town of Jonestown, Guyana Why would people be so committed to him that they would participate in a mass suicide? What does this say about leadership? Trait Approach to Leadership If a person has certain traits, they will be a more effective leader Big Five personality traits with leadership potential include: Extraversion Conscientiousness Openness to experience Ambition Energy
  • 2. The trait approach to leadership seems to be best able to predict leader emergence rather than leader effectiveness There is a difference between possessing a trait and being perceived to possess a trait 4 Leadership Behaviors The behavioral approach to leadership examines what leaders actually do and the behaviors leaders use to achieve their goals It’s a matter of what you do (behavior theory), rather than who you are (trait theory) as a leader Critical Thinking Questions – Traits and Behaviors How does the perspective that leadership is something you do versus something you are change the responsibilities of a leader? The University of Michigan and Ohio State Studies Initiating Structure Extent to which a leader defines and structures the roles of employees in the goal attainment effort Production-oriented leaders have behavior similar to initiating structure Consideration Leader respects employees’ thoughts, ideas, and feelings,
  • 3. expresses appreciation and support, and develops an environment of mutual trust Employee-oriented leaders also value consideration Managerial Grid Contingent Approaches to Leadership Questions examined by contingency theorists include: What are the situational factors that actually matter in leadership? To what leadership styles do they best connect? Least Preferred Co-Worker Fiedler (1967) developed Least preferred co-worker (LPC) questionnaire Rating “least” preferred coworker harshly = task-oriented leader Rating “least” preferred coworker benevolently = relationship- oriented Once individual leadership style is assessed, the situation is determined through three dimensions: 1) Leader-member relations 2) Task structure 3) Position power Critical Thinking Questions – Least Preferred Why does the way a person treats the least preferred co-worker likely say the most about their style of leadership? Think about your experiences working in groups. How did you feel about the least-preferred group member? What kind of leader are you likely to be based on this?
  • 4. Leader-Member Exchange Leader-Member Exchange Theory demonstrates how leaders can create their own context, by creating in-groups and out-groups amongst their own employees In-Group members receive trust, openness in communication, and high levels of interactions with the leader Out-Group members receive less leader attention, more formalistic relations, and are generally not provided the same resources and encouragement in their skill development 12 Situational Leadership Style of leadership should consider the maturity of one’s subordinates Model includes four leadership quadrants: Telling (low maturity employees) to Selling (low to moderate maturity employees) to Participating (moderate to high maturity employees) to Delegating (high maturity employees) Continuum of Leadership Behavior Continuum of Leadership Behavior
  • 5. A successful manager or leader must be able to match his or her behavior to the specific situation in which they find themselves From managers making and announcing decisions to… Subordinates allowed to do so within the limits defined by their superior Charismatic Leadership and Transformational Approaches Attempt to blend three questions into a more unified and integrated approach: Is leadership who we are? Is leadership what we do? Is leadership the relationship between the leader and situation? Charismatic Leadership Theory Asserts that followers attribute extraordinary (even heroic) leadership abilities to leaders when they observe a certain combination of leader behaviors, including: They articulate a vision discrepant from the status quo They take personal risks to achieve that vision They demonstrate a sensitivity to followers’ needs And they exhibit unconventional behavior to galvanize the attention of employees and demonstrate the leader’s goals and values Transformation Leadership Theory Transactional leaders guide their followers by clarifying role and task requirements by using: Laissez Fair leadership Management by exception leadership
  • 6. Contingent reward leadership Transformational leadership builds on this, and inspires follower effort to transcend their self-interest for the good of the organization Individualized consideration, Intellectual stimulation, Inspirational motivation, Idealized influence Authentic Leadership Authentic leadership focuses on the moral aspects of being a leader, and addresses downfalls of charismatic leadership, that leaders can be self-interested Authentic behaviors produce trust, encouraging people have faith in the leaders who use them Enhanced trust enhances information sharing, effectiveness, and productivity Challenges to the Leadership Construct – Attributions, Substitutes and Neutralizers Attribution theory of leadership suggests that leadership is simply an attribution that people make about other individuals Further, leader behaviors may not be as relevant in all organizational situations There are substitutes and neutralizers that can limit the effects of leader behavior For example, leadership may be less effective or needed if employees are extremely experienced in their jobs, with high levels of training and ability, are cohesive, and intrinsically motivated with strong levels of professional orientation. If employees exhibit individual indifference toward organizational
  • 7. rewards, or their jobs are highly structured or routinized and provide their own feedback, the effects of leadership may also be less significant. Finally, the physical separation of the leader may have muting effects on leadership. 19 Case Study: Lead with LUV Colleen Barrett, President of Southwest Airlines, described leadership in the following way: “LUV is our symbol on the New York Stock Exchange. We first started flying out of Love Field in Dallas, and our first advertising slogan in 1972 was “Southwest Airlines, the Someone Else Up There Who LUVs You.” We also had a heart on our first signature line and letterhead. And today, forty years later, we still have our hearts on our aircraft. So, frankly, if you have a need to put a label on what I do, I would prefer that you call me a LUVing Leader.” Leading Change A constant in life is that things change, and many people do not like it People are uncomfortable with change because of the unknown Good leaders must be willing to adapt and adjust to change Good leaders must also try to avoid disasters while managing change Vital Aspects of Leading Being a visionary is one way to be a leader, especially during times of change Translating vision into reality requires anchoring, implementing, and executing a vision Good leaders also empower others, especially during times of change
  • 8. Leadership is about translating intention and vision into reality Strong communication skills are necessary to be a good leader Listening, Leadership, and Change Listening is vital if any leader is going to be truly effective Especially important during times of change when there is fear of the unknown Good leaders understand that listening, even if it means hearing about our weaknesses, is vital to effective and meaningful interaction Leaders should help followers develop into leaders themselves The Distinction Between Leadership and Management Leadership and management are not the same Leadership is the ability to influence a group toward the achievement of a vision or set of goals Management is a broader concept that focuses on planning, organizing, and controlling functions within organizations Context Matters For Profit Organizations Larger corporations tend to have many levels and dimensions of leadership Small Businesses Leadership may be shared and decisions made more quickly because there are fewer levels Non-Profit Organizations Specific values tend to guide and limit leadership Government Sector
  • 9. Guided by unique rules that impact leadership decisions Infrastructure Security Chapter 10 Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Objectives (1 of 2) Construct networks using different types of network devices. Enhance security using security devices. Understand virtualization concepts. Enhance security using NAC/NAP methodologies. Identify the different types of media used to carry network signals. Describe the different types of storage media used to store information. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 2
  • 10. Objectives (2 of 2) Use basic terminology associated with network functions related to information security. Describe the different types and uses of cloud computing. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 3 Key Terms (1 of 3) Basic packet filtering Bridge Cloud computing Coaxial cable Collision domain Concentrator Data loss prevention (DLP) Firewall Hypervisor Hub Infrastructure as a Service (IaaS) Internet content filters Load balancer Modem Network access control Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved.
  • 11. Basic packet filtering – Filtering that looks at each packet entering or leaving the network and then either accepts the packet or rejects the packet based on user-defined rules. Each packet is examined separately. Bridge – A network device that separates traffic into separate collision domains at the data layer of the OSI model. Cloud computing – The automatic provisioning of on demand computational resources across a network. Coaxial cable – A network cable that consists of a solid center core conductor and a physical spacer to the outer conductor which is wrapped around it. Commonly used in video systems. Collision domain – An area of shared traffic in a network where packets from different conversations can collide. Concentrator – A device used to manage multiple similar networking operations, such as provide a VPN endpoint for multiple VPNs. Data loss prevention (DLP) – Technology, processes, and procedures designed to detect when unauthorized removal of data from a system occurs. DLP is typically active, preventing the loss of data, either by blocking the transfer or dropping the connection. Firewall – A network device used to segregate traffic based on rules. Hypervisor - A low-level program that allows multiple operating systems to run concurrently on a single host computer. Hub – A network device used to connect devices at the physical layer of the OSI model. Infrastructure as a Service (IaaS) – The automatic, on-demand provisioning of infrastructure elements, operating as a service; a common element of cloud computing. Internet content filters – A content-filtering system use to protect corporations from employees’ viewing of inappropriate or illegal content at the workplace and the subsequent complications that occur when such viewing takes place.
  • 12. Load balancer – A network device that distributes computing across multiple computers. Modem – A modulator/demodulator that is designed to connect machines via telephone-based circuits. Network access control – An approach to endpoint security that involves monitoring and remediating endpoint security issues before allowing an object to connect to a network. 4 Key Terms (2 of 3) Network Access Protection (NAP) Network Admission Control (NAC) Network-Attached Storage (NAS) Network interface card (NIC) Network operations center (NOC) Next-generation firewall Platform as a Service (PaaS) Private branch exchange (PBX) Proxy server Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Network Access Protection (NAP) – A Microsoft approach to network access control. Network Admission Control (NAC) – The Cisco technology approach for generic network access control. Network-Attached Storage (NAS) – The connection of storage to a system via a network connection. Network interface card (NIC) – A piece of hardware designed to connect machines at the physical layer of the OSI model. Network operations center (NOC) – A control point from where
  • 13. network performance can be monitored and managed. Next-generation firewall – Firewall technology based on packet contents as opposed to simple address and port information. Platform as a Service (PaaS) – The concept of having provisionable operational platforms that can be obtained via a service. Private branch exchange (PBX) – A telephone exchange that serves a specific business or entity. Proxy server – A server that acts as a proxy for individual requests and is used for performance and security purposes in a scalable fashion. 5 Key Terms (3 of 3) Router Sandboxing Servers Shielded twisted-pair (STP) Software as a Service (SaaS) Solid-state drive (SSD) Switch Unified threat management (UTM) Unshielded twisted-pair (UTP) Virtualization Web security gateway Wireless access point Workstation Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved.
  • 14. Router – A network device that operates at the network layer of the OSI model. Sandboxing – The concept of isolating a system and specific processes form the OS in order to provide specific levels of security. Servers – The computers in a network that host applications and data for everyone to share. Shielded twisted-pair (STP) – A physical network connection consisting of two wires twisted and covered with a shield to prevent interference. Software as a Service (SaaS) – The provisioning of software as a service, commonly known as on-demand software. Solid-state drive (SSD) – A mass storage device, such as a hard drive, that is composed of electronic memory as opposed to a physical device of spinning platters. Switch – A network device that operates at the data layer of the OSI model. Unified threat management (UTM) – The aggregation of multiple network security products into a single appliance for efficiency purposes. Unshielded twisted-pair (UTP) – A form of network cabling in which pairs of wires are twisted to reduce crosstalk. Commonly used in LANs. Virtualization – An abstraction of the OS layer, creating the ability to host multiple OSs on a single piece of hardware. Web security gateway – A device that combines proxy functions with content-filtering functions with the intention of addressing the security threats and pitfalls unique to web-based traffic. Wireless access point – A network access device that facilitates the connection of wireless devices to a network. Workstation – The machine that sits on the desktop and is used every day for sending and reading e-mail, creating spreadsheets, writing reports in a word processing program, and playing games. 6
  • 15. Devices Devices are needed to connect clients and servers and to regulate the traffic between them. Devices expand the network beyond simple client computers and servers. Devices come in many forms and with many functions. Each device has a specific network function and plays a role in maintaining network infrastructure security. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. A complete network computer solution in today’s business environment consists of more than just client computers and servers. Devices are needed to expand a network beyond simple client computers and servers to include yet other devices, such as wireless and handheld systems. Devices come in many forms and with many functions, from hubs and switches, to routers, wireless access points, and special-purpose devices such as virtual private network (VPN) devices. 7 Workstations The workstation is the machine that sits on the desktop. It is used every day for sending and reading e-mail, creating spreadsheets, writing reports in a word processing program, and playing games. A workstation connected to a network is an important part of
  • 16. the network security solution. Many threats to information security can start at a workstation, but much can be done in a few simple steps to provide protection from many of these threats. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Most users are familiar with the client computers used in the client/server model called workstation devices. 8 Servers Servers are the computers in a network that host applications and data for everyone to share. Servers come in many sizes. Server operating systems range from Windows Server, to UNIX, to Multiple Virtual Storage (MVS) and other mainframe operating systems They tend to be more robust than workstation OSs. They are designed to service multiple users over a network at the same time. Servers can host a variety of applications. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Servers come in many sizes, from small single-CPU boxes that may be less powerful than a workstation, to multiple-CPU monsters, up to and including mainframes.
  • 17. The operating systems used by servers range from Windows Server, to UNIX, to Multiple Virtual Storage (MVS) and other mainframe operating systems. The OS on a server tends to be more robust than the OS on a workstation system and is designed to service multiple users over a network at the same time. Servers can host a variety of applications, including web servers, databases, e-mail servers, file servers, print servers, and application servers for middleware applications. 9 Mobile Devices Mobile devices such as laptops, tablets, and mobile phones are the latest devices to join the corporate network. Mobile devices can create a major security gap, as a user may access separate e-mail accounts, one personal, without antivirus protection, and the other corporate. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Device Security, Common Concerns As more and more interactive devices are being designed, a new threat source has appeared. Default accounts and passwords are well known in the hacker community. First steps you must take to secure such devices is to change the default credentials.
  • 18. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. In an attempt to build security into devices, typically, a default account and password must be entered to enable the user to access and configure the device remotely. These default accounts and passwords are well known in the hacker community, so one of the first steps you must take to secure such devices is to change the default credentials. Anyone who has purchased a home office router knows the default configuration settings and can check to see if another user has changed theirs. If they have not, this is a huge security hole, allowing outsiders to “reconfigure” their network devices. 11 Network-Attached Storage Because of the speed of today’s Ethernet networks, it is possible to manage data storage across the network. This has led to a type of storage known as Network- Attached Storage (NAS). The combination of inexpensive hard drives, fast networks, and simple application-based servers has made NAS devices in the terabyte range affordable for even home users. As a network device, it is susceptible to attacks. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Because of the large size of video files, this has become popular for some users as a method of storing TV and video libraries. Because NAS is a network device, it is susceptible to various
  • 19. attacks, including sniffing of credentials and a variety of brute - force attacks to obtain access to the data. 12 Removable Storage Removable devices can move data outside of the corporate- controlled environment. Removable devices can bring unprotected or corrupted data into the corporate environment. All removable devices should be scanned by antivirus software upon connection to the corporate environment. Corporate policies should address the copying of data to removable devices. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Many mobile devices can be connected via USB to a system and used to store data—and in some cases vast quantities of data. This capability can be used to avoid some implementations of data loss prevention mechanisms. 13 Virtualization (1 of 2) Virtualization technology is used to allow a computer to have more than one OS present and, in many cases, operating at the same time. Virtualization is an abstraction of the OS layer. It creates the ability to host multiple OSs on a single piece of hardware. A major advantage of virtualization is the separation of the software and the hardware. It creates a barrier that can improve many system functions,
  • 20. including security. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 14 Virtualization (2 of 2) The underlying hardware is referred to as the host machine, and on it is a host OS. A hypervisor is needed to manage virtual machines (VMs). Virtual machines are typically referred to as the guest OSs. Newer OSs are designed to natively incorporate virtualization hooks. Common virtualization solutions include: Microsoft Hyper-V, VMware, Oracle VM VirtualBox, Parallels, and Citrix Xen Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Exam Tip: A hypervisor is the interface between a virtual machine and the host machine hardware. Hypervisors are the layer that enables virtualization. Either the host OS has built-in hypervisor capability or an application is needed to provide the hypervisor function to manage the virtual machines (VMs).
  • 21. Newer OSs are designed to natively incorporate virtualization hooks, enabling virtual machines to be employed with greater ease. 15 Hypervisor (1 of 4) A hypervisor enables virtualization. A low-level program that allows multiple operating systems to run concurrently on a single host computer. The hypervisor acts as the traffic cop that controls I/O and memory management. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 16 Hypervisor (2 of 4) Major advantages of virtualization: The separation of the software and the hardware Creates a barrier that can improve many system functions, including security. Either the host OS has built-in hypervisor capability or an application is needed to provide the hypervisor function to manage the virtual machines (VMs). Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved.
  • 22. 17 Hypervisor (3 of 4) Type 1 Type 1 hypervisors run directly on the system hardware. Referred to as a native, bare-metal, or embedded hypervisors in typical vendor literature. Are designed for speed and efficiency, as they do not have to operate through another OS layer. These platforms come with management toolsets to facilitate VM management in the enterprise. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 18 Hypervisor (4 of 4) Type 2 Type 2 hypervisors run on top of a host operating system. In the beginning, Type 2 hypervisors were the most popular. Typical Type 2 hypervisors include Oracle’s VirtualBox and VMware’s VMware Workstation Player. Are designed for limited numbers of VMs, typically in a desktop or small server environment. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved.
  • 23. 19 Application Cells/Containers Application cells/containers holds the portions of an OS that it needs separate from the kernel. Multiple containers can share an OS and have separate memory, CPU, and storage threads. A container consists of an entire runtime environment The application platform, including its dependencies, is containerized Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 20 VM Sprawl Avoidance Sprawl is the uncontrolled spreading of disorganization caused by a lack of an organizational structure when many similar elements require management. VM sprawl is a symptom of a disorganized structure. VM sprawl avoidance needs to be implemented via policy. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved.
  • 24. 21 VM Escape Protection VM escape occurs when software (typically malware) or an attacker escapes from one VM to the underlying OS and then resurfaces in a different VM. Large-scale VM environments have specific modules designed to detect escape and provide VM escape protection to other modules. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 22 Snapshots A snapshot is a point-in-time saving of the state of a virtual machine. Snapshots uses: Roll a system back to a previous point in time Undo operations Provide a quick means of recovery from a complex, system- altering change that has gone awry Snapshots act as a form of backup and are typically much faster than normal system backup and recovery operations. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved.
  • 25. 23 Patch Compatibility Patches are still needed and should be applied, independent of the virtualization status. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 24 Host Availability/Elasticity In a virtualization environment, protecting the host OS and hypervisor level is critical for system stability. Best practice is to avoid the installation of any applications on the host-level machine. Elasticity refers to the ability of a system to expand/contract as system requirements dictate. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 25 Security Control Testing
  • 26. It is important to test the controls applied to a system to manage security operations to ensure that they are providing the desired results. It is essential to specifically test all security controls inside the virtual environment to ensure their behavior is still effective. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 26 Sandboxing Sandboxing refers to the quarantine or isolation of a system from its surroundings. Virtualization can be used as a form of sandboxing with respect to an entire system. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 27 Networking Networks are used to connect devices together. Networks are composed of components that perform networking functions to move data between devices.
  • 27. Networks begin with network interface cards, then continue in layers of switches and routers. Specialized networking devices are used for specific purposes, such as security and traffic management. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 28 Network Interface Cards (1 of 2) To connect a server or workstation to a network, a device known as a network interface card (NIC) is used. A NIC is the physical connection between a computer and the network. Each NIC port is serialized with a unique code, 48 bits long, referred to as a Media Access Control address (MAC address). Unfortunately, these addresses can be changed, or “spoofed,” rather easily. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. A NIC is a card with a connector port for a particular type of network connection, either Ethernet or Token Ring. The most common network type in use for LANs is the Ethernet protocol, and the most common connector is the RJ-45 connector. The purpose of a NIC is to provide lower-level protocol
  • 28. functionality from the OSI (Open System Interconnection) model. Because the NIC defines the type of physical layer connection, different NICs are used for different physical protocols. NICs come as single-port and multiport, and most workstations use only a single-port NIC, as only a single network connection is needed. For servers, multiport NICs are used to increase the number of network connections, increasing the data throughput to and from the network. Each NIC port is serialized with a unique code, 48 bits long, referred to as a Media Access Control address (MAC address). These are created by the manufacturer, with 24 bits representing the manufacturer and 24 bits being a serial number, guaranteeing uniqueness. MAC addresses are used in the addressing and delivery of network packets to the correct machine and in a variety of security situations. Unfortunately, these addresses can be changed, or “spoofed,” rather easily. In fact, it is common for personal routers to clone a MAC address to allow users to use multiple devices over a network connection that expects a single MAC. 29 Network Interface Cards (2 of 2) Figure 10.1 Linksys network interface card (NIC) Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved.
  • 29. This figure shows a common form of a NIC. 30 Hubs A hub is networking equipment that connects devices that are using the same protocol at the physical layer of the OSI model. A hub allows multiple machines in an area to be connected together in a star configuration with the hub at the center. All connections on a hub share a single collision domain, a small cluster in a network where collisions occur. Increased network traffic can become limited by collisions; this problem has made hubs obsolete in newer networks. Hubs also create a security weakness due to sniffing and eavesdropping issues. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. A hub configuration can save significant amounts of cable and is an efficient method of configuring an Ethernet backbone. The collision issue has made hubs obsolete in newer, higher performance networks, with inexpensive switches and switched Ethernet keeping costs low and usable bandwidth high. Hubs also create a security weakness in that all connected devices see all traffic, enabling sniffing and eavesdropping to occur. In today’s networks, hubs have all but disappeared, being replaced by low-cost switches. 31 Bridges A bridge operates at the data link layer, filtering traffic based on MAC addresses.
  • 30. Bridges can reduce collisions by separating pieces of a network into two separate collision domains. This only cuts the collision problem in half. A better solution is to use switches for network connections. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Bridges are networking equipment that connect devices using the same protocol at the data link layer of the OSI model. 32 Switches (1 of 4) A switch forms the basis for connections in most Ethernet-based LANs. Switches have replaced hubs and bridges. A switch has separate collision domains for each port. When full duplex is employed, collisions are virtually eliminated from the two nodes, host and client. A switch is usually a Layer 2 device, but Layer 3 switches incorporate routing functionality. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. A switch has separate collision domains for each port. This means that for each port, two collision domains exist: one from the port to the client on the downstream side, and one from the switch to the network upstream. When full duplex is employed, collisions are virtually eliminated from the two nodes, host and
  • 31. client. This also acts as a hub-based system, where a single sniffer can see all of the traffic to and from connected devices. Switches operate at the data link layer, while routers act at the network layer. For intranets, switches have become what routers are on the Internet—the device of choice for connecting machines. As switches have become the primary network connectivity device, additional functionality has been added to them. A switch is usually a Layer 2 device, but Layer 3 switches incorporate routing functionality. 33 Switches (2 of 4) Advantages of switches They improve network performance by filtering traffic. They provide the option to disable a port so that it cannot be used without authorization. They support port security allowing the administrator to control which systems can send data to each of the ports. Switches use the MAC address of the systems to incorporate traffic filtering and port security features. Port address security based on MAC addresses functionality is what allows an 802.1X device to act as an “edge device.” Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. A switch filters traffic by only sending the data to the port on the switch that the destination system resides on. The switch knows what port each system is connected to and sends the data only to that port. The switch uses the MAC address of the systems to incorporate
  • 32. traffic filtering and port security features, which is why it is considered a Layer 2 device. Port address security based on MAC addresses can determine whether a packet is allowed or blocked from a connection. This is the very function that a firewall uses for its determination, and this same functionality is what allows an 802.1X device to act as an “edge device.” 34 Switches (3 of 4) Switch security concerns They are intelligent network devices and are therefore subject to hijacking by hackers. Switches are commonly administered using the Simple Network Management Protocol (SNMP) and Telnet protocol. Both protocols have a serious weakness in that they send passwords across the network in cleartext. Switches are shipped with default passwords. Switches are subject to electronic attacks, such as ARP poisoning and MAC flooding. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. One of the security concerns with switches is that, like routers, they are intelligent network devices and are therefore subject to hijacking by hackers. Should a hacker break into a switch and change its parameters, he might be able to eavesdrop on specific or all communications, virtually undetected. Switches are commonly administered using the Simple Network Management Protocol (SNMP) and Telnet protocol, both of which have a serious weakness in that they send passwords across the
  • 33. network in cleartext. A hacker armed with a sniffer that observes maintenance on a switch can capture the administrative password. This allows the hacker to come back to the switch later and configure it as an administrator. An additional problem is that switches are shipped with default passwords, and if these are not changed when the switch is set up, they offer an unlocked door to a hacker. Switches are also subject to electronic attacks, such as ARP poisoning and MAC flooding. ARP poisoning is where a device spoofs the MAC address of another device, attempting to change the ARP tables through spoofed traffic and the ARP table- update mechanism. MAC flooding is where a switch is bombarded with packets from different MAC addresses, flooding the switch table and forcing the device to respond by opening all ports and acting as a hub. This enables devices on other segments to sniff traffic. 35 Switches (4 of 4) Loop protection is a concern with switches. Switches operate at Layer 2 so there is no countdown mechanism to kill packets that get caught in loops or on paths that will never resolve. The Layer 2 space acts as a mesh, where potentially the addition of a new device can create loops in the existing device interconnections. Spanning trees technology is employed to prevent loops. The Spanning Tree Protocol (STP) allows for multiple, redundant paths, while breaking loops to ensure a proper broadcast pattern. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved.
  • 34. 36 Routers (1 of 2) A router is a network traffic management device used to connect different network segments. Operate at the network layer (Layer 3) of the OSI model Form the backbone of the Internet Use algorithms and tables to determine where to send the packet Use access control lists (ACLs) as a method of deciding whether a packet is allowed to enter the network Must limit router access and control of internal functions Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Routers operate at the network layer (Layer 3) of the OSI … Network Fundamentals Chapter 9 Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved.
  • 35. Objectives Identify the basic network architectures. Define the basic network protocols. Explain routing and address translation. Classify security zones. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 2 Key Terms (1 of 3) Address Resolution Protocol (ARP) Bus topology Datagram Denial-of-service (DoS) Domain Name System (DNS) DMZ Dynamic Host Configuration Protocol (DHCP) Enclave Ethernet Extranet Flat network Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Address Resolution Protocol (ARP) – A protocol in the TCP/IP suite specification used to map an IP address to a Media Access
  • 36. Control (MAC) address. Bus topology – A network layout in which a common line (the bus) connects devices. Datagram – A packet of data that can be transmitted over a packet-switched system in a connectionless mode. Denial-of-service (DoS) – An attack in which actions are taken to deprive authorized individuals from accessing a system, its resources, the data it stores or processes, or the network to which it is connected. Domain Name System (DNS) – An attack in which actions are taken to deprive authorized individuals from accessing a system, its resources, the data it stores or processes, or the network to which it is connected. DMZ – A network segment that exists in a semi-protected zone between the Internet and the inner, secure trusted network. Dynamic Host Configuration Protocol (DHCP) – An Internet Engineering Task Force (IETF) Internet Protocol (IP) specification for automatically allocating IP addresses and other configuration information based on network adapter addresses. It enables address pooling and allocation and simplifies TCP/IP installation and administration. Enclave – A section of a network that serves a specific purpose and is isolated by protocols from other parts of a network. Ethernet – The common name for the IEEE 802.3 standard method of packet communication between two nodes at layer 2. Extranet – an extension of a selected portion of a company’s intranet to external partners. Flat network – A network design that avoids packet-looping issues through an architecture that does not have tiers. 3 Key Terms (2 of 3) Internet Control Message Protocol (ICMP) Internet Protocol (IP) Intranet Local area network (LAN)
  • 37. Media Access Control (MAC) address Mixed topology Network Network Address Translation (NAT) Packet Protocol Ring topology Routing Star topology Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Internet Control Message Protocol (ICMP) – One of the core protocols of the TCP/IP protocol suite, used for error reporting and status messages. Internet Protocol (IP) – The network layer protocol used by the Internet for routing packets across a network. Intranet – a private, internal network that uses common network technologies (such as HTTP, FTP, and so on) to share information and provide resources to organizational users. Local area network (LAN) – A grouping of computers in a network structure confined to a limited area and using specific protocols, such as Ethernet for OSI Layer 2 traffic addressing. Media Access Control (MAC) address – The data link layer address for local network addressing. Mixed topology - Larger networks, such as those inside an office complex, may use more than one topology at the same time. Network – A means to connect two or more computers together for the purposes of sharing network information. Network Address Translation (NAT) – A method of
  • 38. readdressing packets in a network at a gateway point to enable the use of local nonroutable IP addresses over a public network such as the Internet. Packet – Smaller pieces of data used for transmission resulting from the breaking up of larger data. Protocol – An agreed-upon format for exchanging or transmitting data between systems, enable computers to communicate. Ring topology – A network layout in which network components are connected to each other in a closed loop with each device directly connected to two other devices. Routing – That process of moving packets from one network to another. Star topology – A network topology where network components are connected to a central point. 4 Key Terms (3 of 3) Storage area network (SAN) Subnet mask Subnetting Three-way handshake Topology Transmission Control Protocol (TCP) Trunking Tunneling User Datagram Protocol (UDP) Virtual local area network (VLAN) Wide area network (WAN) Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved.
  • 39. Storage area network (SAN) – A technology-based storage solution consisting of network attached storage. Subnetting – The creation of a network within a network by manipulating how an IP address is split into network and host portions. Subnet mask – The information that tells a device how to interpret the network and host portions of an IP address. Three-way handshake – A means of ensuring information transference through a three-step data exchange. Used to initiate a TCP connection. Topology – Describes how the network is physically or logically arranged. Transmission Control Protocol (TCP) – The connection-oriented transport layer protocol for use on the Internet that allows packet-level tracking of a conversation. Trunking – The process of spanning a single VLAN across multiple switches. Tunneling – The process of packaging packets so that they can traverse a network in a secure, confidential manner. User Datagram Protocol (UDP) – A protocol in the TCP/ IP protocol suite for the transport layer that does not sequence packets—it is “fire and forget” in nature. Virtual local area network (VLAN) – A broadcast domain inside a switched system. Wide area network (WAN) – A network that spans a large geographic region. 5 Introduction By the simplest definition in the data world, a network is a means to connect two or more computers together for the purposes of sharing information. The term “network” has different meanings depending on the context and usage. Though data networks vary widely in size and scope, they are generally defined in terms of their architecture, topology, and
  • 40. protocol. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Network sizes and shapes vary drastically—from two personal computers connected with a crossover cable or wireless router to the Internet, encircling the globe and linking together untold numbers of individual, distributed systems. 6 Network Architectures (1 of 3) A local area network (LAN) typically is smaller in terms of size and geographic coverage and consists of two or more connected devices. Home networks and most small office networks can be classified as LANs. A wide area network (WAN) tends to be larger, covering more geographic area, and consists of two or more systems in geographically separated areas. They are connected by leased lines, radio waves, satellite relays, microwaves, or even dial-up connections. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Exam Tip: A LAN is a local area network—an office building, home network, and so on. A WAN is a wide area network—a corporate network connecting offices in Dallas, New York, and San Jose, for example.
  • 41. Every network has an architecture—whether by design or by accident. Defining or describing a specific network’s architecture involves identifying the network’s physical configuration, logical operation, structure, procedures, data formats, protocols, and other components. For the sake of simplicity and categorization, people tend to divide network architectures into two main categories: LANs and WANs. 7 Network Architectures (2 of 3) Figure 9.1 Corporate WAN connecting multiple offices Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Most corporations have multiple LANs within each office location that all connect to a WAN that provides intercompany connectivity. This figure shows an example of a corporate network. Each office location will typically have one or more LANs, which are connected to the other offices and the company headquarters through a corporate WAN. 8 Network Architectures (3 of 3) Specialized network structures are classified by size and use. Campus area network (CAN) Intranet Internet Metropolitan area network (MAN)
  • 42. Storage area network (SAN) Virtual local area network (VLAN) Client/server Peer-to-peer Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Over time, as networks have grown, diversified, and multiplied, the line between LAN and WAN has become blurred. To better describe emerging, specialized network structures, new terms have been coined to classify networks based on size and use: Campus area network (CAN) – A network connecting any number of buildings in an office or university complex (also referred to as a campus wide area network). Intranet – A “private” network that is accessible only to authorized users. Many large corporations host an intranet to facilitate information sharing within their organization. Internet – The “global network” connecting hundreds of millions of systems and users. Metropolitan area network (MAN) – A network designed for a specific geographic locality such as a town or a city. Storage area network (SAN) – A high-speed network connecting a variety of storage devices such as tape systems, RAID arrays, optical drives, file servers, and others. Virtual local area network (VLAN) – A logical network allowing systems on different physical networks to interact as if they were connected to the same physical network. Client/server – A network in which powerful, dedicated systems called servers provide resources to individual workstations or clients. Peer-to-peer – A network in which every system is treated as an equal, such as a home network.
  • 43. 9 Network Topology (1 of 5) Topology refers to how the network is physically or logically arranged. The main classes of network topologies are: Star topology – components connected to a central point Bus topology – components connected to the same cable, often called “the bus” or “the backbone” Ring topology – components connected to each other in a closed loop with each device directly connected to two other devices Mixed topology – uses more than one topology Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 10 Network Topology (2 of 5) Figure 9.2 Star topology Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 11 Network Topology (3 of 5)
  • 44. Figure 9.3 Bus topology Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 12 Network Topology (4 of 5) Figure 9.4 Ring topology Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 13 Network Topology (5 of 5) Figure 9.5 Mixed topology Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Larger networks, such as those inside an office complex, may
  • 45. use more than one topology at the same time. For example, an office complex may have a large ring topology that interconnects all the buildings in the complex. Each building may have a large bus topology to interconne ct star topologies located on each floor of the building. This is called a mixed topology or hybrid topology. 14 Wireless Wireless networking is the transmission of packetized data by means of a physical topology that does not use direct physical links. Hub-and-spoke: wireless access point is the hub and is connected to the wired network Mesh: wireless units talk directly to each other, without a central access point Ad-Hoc: systems on the network direct packets to and from their source and target locations without using a central router or switch Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 15 Network Protocols When engineers first started to connect computers together via networks, they quickly realized they needed a commonly accepted method for communicating—a protocol.
  • 46. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 16 Protocols (1 of 4) A protocol is an agreed-upon format for exchanging or transmitting data between systems. A protocol defines a number of agreed-upon parameters, such as the data compression method, the type of error checking to use, and mechanisms for systems to signal when they have finished either receiving or transmitting data. Most networks are dominated by Ethernet and Internet Protocol. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 17 Protocols (2 of 4) AppleTalk Asynchronous Transfer Mode (ATM) Ethernet Fiber Distributed Data Interface (FDDI) Internet Protocol (IP) Internetwork Packet Exchange (IPX) Signaling System 7 (SS7) Systems Network Architecture (SNA) Token Ring
  • 47. Transmission Control Protocol/Internet Protocol (TCP/IP) X.25A protocol Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. There is a wide variety of protocols, each designed with certain benefits and uses in mind. Some of the more common protocols that have been used in networking are: AppleTalk – The communications protocol developed by Apple to connect Macintosh computers and printers. Asynchronous Transfer Mode (ATM) – A protocol based on transferring data in fixed-size packets. The fixed packet sizes help ensure that no single data type monopolizes the available bandwidth. Ethernet – The LAN protocol developed jointly by Xerox, DEC, and Intel—the most widely implemented LAN standard. Fiber Distributed Data Interface (FDDI) – The protocol for sending digital data over fiber-optic cabling. Internet Protocol (IP) – The protocols for managing and transmitting data between packet-switched computer networks, originally developed for the Department of Defense. Most users are familiar with Internet protocols such as e-mail, File Transfer Protocol (FTP), Telnet, and Hypertext Transfer Protocol (HTTP). Internetwork Packet Exchange (IPX) – The networking protocol created by Novell for use with Novell NetWare operating systems. Signaling System 7 (SS7) – The telecommunications protocol used between private branch exchanges (PBXs) to handle tasks such as call setup, routing, and teardown. Systems Network Architecture (SNA) – A set of network protocols developed by IBM, originally used to connect IBM’s
  • 48. mainframe systems. Token Ring – A LAN protocol developed by IBM that requires systems to possess the network “token” before transmitting data. Transmission Control Protocol/Internet Protocol (TCP/IP) – The collection of communications protocols used to connect hosts on the Internet. TCP/IP is by far the most commonly used network protocol and is a combination of the TCP and IP protocols. X.25A protocol – Developed by the Comité Consultatif International Téléphonique et Télégraphique (CCITT) for use in packet-switched networks. The CCITT was a subgroup within the International Telecommunication Union (ITU) before the CCITT was disbanded in 1992. 18 Protocols (3 of 4) In most cases, communications protocols were developed around the Open System Interconnection (OSI) model. OSI defines a framework for implementing protocols and networking components in seven distinct layers. Control is passed from one layer to another (top-down) before it exits one system and enters another system, where control is passed bottom-up to complete the communications cycle. Most protocols only loosely follow the OSI model. Several protocols combine one or more layers. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. The OSI model, or OSI Reference Model, is an International Organization for Standardization (ISO) standard for worldwide communications that defines a framework for implementing protocols and networking components in seven distinct layers.
  • 49. The OSI model also provides a certain level of abstraction and isolation for each layer, which only needs to know how to interact with the layer above and below it. The application layer, for example, only needs to know how to communicate with the presentation layer—it does not need to talk directly to the physical layer. 19 Protocols (4 of 4) Figure 9.6 The OSI Reference Model Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. This figure shows the different layers of the OSI model. 20 Packets (1 of 4) Large chunks of data must typically be broken up into smaller, more manageable chunks before they are transmitted from one computer to another. Advantages of breaking the data up include: More effective sharing of bandwidth with other systems Not needing to retransmit the entire dataset if there is a problem in transmission When data is broken up into smaller pieces for transmission, each of the smaller pieces is typically called a packet. Principles of Computer Security, Fifth Edition
  • 50. Copyright © 2018 by McGraw-Hill Education. All rights reserved. Networks are built to share information and resources, but like other forms of communication, networks and the protocols they use have limits and rules that must be followed for effective communication. Each protocol has its own definition of a packet—dictating how much data can be carried, what information is stored where, how the packet should be interpreted by another system, and so on. A standard packet structure is a crucial element in a protocol definition. Without a standard packet structure, systems would not be able to interpret the information coming to them from other systems. Packet-based communication systems have other unique characteristics, such as size, which need to be addressed. This is done via a defined maximum and fragmenting packets that are too big. 21 Packets (2 of 4) Maximum Transmission Unit (MTU) is a factor in determining the number of packets into which a message must be broken. It represents the largest packet that can be carried across a network channel. The value of the MTU is used by TCP to prevent packet fragmentation at intervening devices. Packet fragmentation is the splitting of a packet while in transit into two packets so that they fit past an MTU bottleneck. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights
  • 51. reserved. When transmitting packets across a network, there are many intervening protocols and pieces of equipment, each w ith its own set of limitations. 22 Packets (3 of 4) Packet fragmentation is a method of handling large packets. Internet Protocol has a mechanism for the handling of packets that are larger than allowed across a hop. Under ICMP v4, a router has two options: Break the packet into two fragments, sending each separately Drop the packet and send an ICMP message back to the originator, indicating that the packet is too big The fragmentation problem can cause excessive levels of packet retransmission. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Built into the Internet Protocol is a mechanism for handling of packets that are larger than allowed across a hop. Under ICMP v4, a router has two options when it encounters a packet that is too large for the next hop: break the packet into two fragments, sending each separately, or drop the packet and send an ICMP message back to the originator, indicating that the packet is too big. When a fragmented packet arrives at the receiving host, it must be reunited with the other packet fragments and reassembled. One of the problems with fragmentation is that it can cause excessive levels of packet retransmission as TCP must retransmit an entire packet for the loss of a single
  • 52. fragment. In IPv6, to avoid fragmentation, hosts are required to determine the minimal path MTU before transmission of packets to avoid fragmentation en route. Any fragmentation requirements in IPv6 are resolved at the origin, and if fragmentation is required, it occurs before sending. 23 Packets (4 of 4) Steps are taken to avoid fragmentation in IPv6. Hosts are required to determine the minimal path MTU before transmission of packets to avoid fragmentation en route. Any fragmentation requirements in IPv6 are resolved at the origin, and if fragmentation is required, it occurs before sending. IP fragmentation can be exploited in a variety of ways to bypass security measures. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. IP fragmentation can be exploited in a variety of ways to bypass security measures. Packets can be purposefully constructed to split exploit code into multiple fragments to avoid IDS detection. Because the reassembly of fragments is dependent upon data in the fragments, it is possible to manipulate the fragments to result in datagrams that exceed the 64KB limit, resulting in denial of service. 24 Internet Protocol (1 of 2) The Internet Protocol (IP) is not a single protocol but a suite of protocols. The two versions of the protocol in use are v4 and v6.
  • 53. There are differences between the two versions. One difference is the replacement of the Internet Group Management Protocol (IGMP) with the Internet Control Message Protocol (ICMP) and Multicast Listener Discovery (MLD) in IPv6 Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 25 Internet Protocol (2 of 2) Figure 9.7 Internet Protocol suite components Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. This figure shows the relationship between some of the IP suite and the OSI model. 26 IP Packets (1 of 2) An IP packet, often called a datagram, has two main sections: Header – contains all of the information needed to describe the packet. Data section – sometimes called the payload
  • 54. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. 27 IP Packets (2 of 2) Figure 9.8 Logical layout of an IP packet, (a) IPv4 (b) IPv6 Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. In IPv6, the source and destination addresses take up much greater room, and for equipment and packet handling reasons, most of the informational options have been moved to the optional area after the addresses. This series of optional extension headers allows the efficient use of the header in processing the routing information during packet routing operations. One of the most common options is the IPsec extension, which is used to establish IPsec connections. IPsec uses encryption to provide a variety of protections to packets. 28 TCP vs. UDP (1 of 4) Two protocols required for Internet’s existence Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) Both protocols run on top of the IP network protocol. As separate protocols, they each have their own packet
  • 55. definitions, capabilities, and advantages. Most important difference between TCP and UDP is the concept of “guaranteed” reliability and delivery. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. Exam Tip: TCP is a “connection-oriented” protocol and offers reliability and guaranteed delivery of packets. UDP is a “connectionless” protocol with no guarantees of delivery. 29 TCP vs. UDP (2 of 4) UDP is known as a “connectionless” protocol. It has very few error recovery services and no guarantee of packet delivery. Sender has no idea whether the packets were successfully received or whether they were received in order. UDP is considered to be an unreliable protocol. UDP is good for time synchronization requests, name lookups, and streaming audio. It is a fairly “efficient” protocol in terms of content delivery versus overhead. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. With UDP, more time and space is dedicated to content (data) delivery than with other protocols such as TCP. This makes UDP a good candidate for streaming protocols, as more of the
  • 56. available bandwidth and resources are used for data delivery than with other protocols. 30 TCP vs. UDP (3 of 4) TCP is a “connection-oriented” protocol specifically designed to provide a reliable connection between two hosts exchanging data. TCP is designed to ensure packets processed in the same order in which they were sent. Packet sequence number shows where each packet fits into the overall conversation. TCP requires systems to follow a specific pattern when establishing communications called the three-way handshake. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. As part of TCP, each packet has a sequence number to show where that packet fits into the overall conversation. With the sequence numbers, packets can arrive in any order and at different times and the receiving system will still know the correct order for processing them. The sequence numbers also let the receiving system know if packets are missing—receiving packets 1, 2, 4, and 7 tells us that packets 3, 5, and 6 are missing and needed as part of this conversation. The receiving system can then request retransmission of packets from the sender to fill in any gaps. The “guaranteed and reliable” aspect of TCP makes it very popular for many network applications and services such as HTTP, FTP, and Telnet. 31
  • 57. TCP vs. UDP (4 of 4) Figure 9.9 TCP’s three-way handshake Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. As part of the connection, TCP requires that systems follow a specific pattern when establishing communications. This pattern, often called the three-way handshake, is a sequence of very specific steps: The originating host (usually called the client) sends a SYN (synchronize) packet to the destination host (usually called the server). The SYN packet tells the server what port the client wants to connect to and the initial packet sequence number of the client. The server sends a SYN/ACK packet back to the client. This SYN/ACK (synchronize/acknowledge) tells the client “I received your request” and also contains the server’s initial packet sequence number. The client responds to the server with an ACK packet to complete the connection establishment process. Note: Think of the three-way handshake as being similar to a phone call. You place a call to your friend—that’s the SYN. Your friend answers the phone and says “hello”—that’s the SYN/ACK. Then you say “Hi, it’s me”—that’s the ACK. Your connection is established and you can start your conversation. 32
  • 58. ICMP (1 of 2) Internet Control Message Protocol (ICMP) is probably the third most commonly used protocol. ICMP is a control and information protocol. It is used by network devices to determine such things as a remote network’s availability, the length of time to reach a remote network, and the best route for packets to take when traveling to that remote network. ICMP can also be used to handle traffic flow. ICMP is a connectionless protocol designed to carry small messages quickly with minimal overhead or impact to bandwidth. Principles of Computer Security, Fifth Edition Copyright © 2018 by McGraw-Hill Education. All rights reserved. During the early development of large networks, it was quickly discovered that there needed to be some mechanism for managing the overall infrastructure —handling connection status, traffic flow, availability, and errors. This mechanism is ICMP. ICMP can also be used to handle the flow of traffic, telling other network devices to “slow down” transmission speeds if packets are coming in too fast. ICMP, like UDP, is a connectionless protocol. ICMP was designed to carry small messages quickly with minimal overhead or impact to bandwidth. 33 ICMP (2 of 2)
  • 59. ICMP has been greatly abused … Chapter 12: Celebrating Diversity Introduction The landscape of the workplace has changed As the United States becomes more diverse, markets, customers, and employees become more diverse Changes in the racial and ethnic makeups of the work environment are significant By 2060 white Americans will only make up 43% of the U.S. population Women are expected to represent the majority of the U.S. workforce by 2020 Case Study: Bass Pro Shop In the mid-2000s, managers at various Bass Pro Shops stores using discriminatory language and hiring practices were reported A lawsuit was filed against the corporation and is still being litigated today What terms make you feel uncomfortable? Does it surprise you that there are still situations like this today? Is this an isolated case? Major Diversity Categories in Organizations Race: Percentage of traditional racial minorities in the U.S. workforce is increasing National origin: Growing proportion of today’s workers are
  • 60. immigrants, and English is not their first language Age: Increasing number of employees expect to work past the traditional retirement age Disability: Firms need to provide reasonable accommodation so workplaces are accessible Religion: Inclusion of diverse religious faiths and customs Sex: Ensure equal access and opportunities in hiring Engaging a Diverse Environment The number of women and people of color in the American workforce is increasing The average age of the American workforce is increasing Diversity encompasses how we think, act, conduct business; more than just what we “look like” The Aging Workforce Between 1977 and 2007, employment of workers 65+ increased 101%, compared to a much smaller increase of 59% for total employment With the aging of the baby-boom generation, the older age cohorts are expected to make up a larger proportion of the labor force in the next two decades This aging workforce impacts the organizational environment in many ways, including stereotypes Organizations are stronger when workers embrace the differences in understandings, experiences, attitudes, and expectations that each generation has to offer Sex and Gender Issues Number of men in the workforce increased by about 53% from 1967-2009 During the same timespan, the number of women in the
  • 61. workforce increased by over 190% Incomes for women in the workforce are rising, but there is still a significant gap between earnings of men and women Institutionalization of masculine male and feminine female complicates understanding It is important to distinguish between sex and gender Critical Thinking Questions – Sex and Gender Why do sex and gender matter in organizational communication? In what ways is masculinity celebrated and/or dismissed in our culture? In the workplace? In what ways is femininity celebrated and/or dismissed in our culture? In the workplace? Racial and Ethnic Issues Higher population growth and increasing participation rates mean minorities in the workforce will increase significantly Discrimination still remains a problem A healthy work environment will develop an understanding and climate that sees all individuals as people of equal worth Disabled Workers American with Disabilities Act (ADA) passed into law in 1990, prohibiting discrimination against individuals with disabilities in all areas of public life Employers must provide reasonable accommodation for disabled employees If a disability is not job-related or can be accommodated, organizations should not discriminate Communication technology is providing additional opportunities that influence the ability of the disabled worker
  • 62. Intercultural Issues Culture: system of shared values, beliefs, and meaning Ethnocentrism: evaluating others’ culture against our own Perception: influences our worldview Stereotyping: judging a person based on the group to which we perceive them as belonging Nonverbal differences: meaning of a symbol in one country may differ in another; a potential barrier Language difference: can even vary between regions Cultural intelligence: adapting, selecting, shaping cultural aspects of environment Critical Thinking Questions - Diversity In what ways have you been discriminated against because of your: Age? Race? Sex or gender? Abilities? What are some of the issues or barriers that prevent us from communicating effectively in intercultural environments? Dealing with Emotion Emotions are intense feelings directed at someone or something Both energy and stability are needed in the workplace Just like personality, a range (or diversity) of emotional response when balanced can help keep an organizational team focused and effective Emotions can help us gauge the effectiveness of potential changes, response to decisions, or buy-in to future projects
  • 63. Understanding Personality Personality describes the sum total of ways in which an individual reacts to and interacts with others One personality type is not better than another – they are just different We must be aware of our own personality and the impact it has on our environment – and make adjustments when necessary Discrimination Stereotypes often lead to workplace discrimination Whether an individual is a person of color or white, male or female, gay or straight, disabled or otherly abled are often extraneous factors not relevant to the organizational or job- related decision at hand When we place individuals or groups of people in categories, we rob them of their uniqueness and individuality Sexual Harassment Sexual harassment is a special abuse of power that we discuss briefly here because it becomes a hindrance to diversity Unwanted sexual advances, requests for sexual favors, and other verbal or physical conduct of a sexual nature that create a hostile or offensive work environment Organizations must train and educate their employees on what sexual harassment is, and what policies and practices exist within the organization and the law to guard against sexual harassment Technology and Diversity
  • 64. Technology can both encourage and hinder diversity Technology can also provide more tools to manage the process to improve communication and a different method of dealing with cross-cultural communication issues and stereotypes A text-only (email or texting) Voice-only (traditional phone) Using a more rich channel of verbal and non-verbal information (voice and physical) Face-to-face or video-conference Organizational Culture and Diversity Organizational Values Organizational values should primarily align with personal values if one is to feel comfortable participating in the organizational environment An appreciation for diversity is vital for organizational success A diversity of ideas and values in regards to the direction and movement of the organization helps leaders make better decisions Leadership and Management Styles Different organizational environments require different types of leadership Even in the same organization, different styles and approaches are necessary with different employees or in different situations Diversity in leadership and management styles is important for organizational success Climate Issues
  • 65. Organizational climate is the shared perception of employees of the properties of the work environment that guide expected behavior Safety, justice, clarity of rules and regulations, as well as clear goals and expectations, help employees understand how they and others fit into the organization It is important for a diverse organization to emphasize the need for a variety of ideas, with standards of performance and expectations of teamwork and encouraging a variety of inputs from diverse sources Working with Difficult People In a diverse work environment, there’s an enhanced likelihood that we are going to work with someone who sees things from a different point of view This is a core benefit of diversity; it is also a personal challenge, as you may have to accomplish tasks with people who you do not understand or agree with Practice the art of active listening, whereby you truly listen to another’s point of view Effective Organizational Diversity Programs Firms can focus on attracting diverse applicants by targeting recruiting messages to specific demographic groups currentl y underrepresented in one’s workforce An effective diversity program will also educate managers about the legal framework of equal employment opportunity, encourage equitable treatment of all employees regardless of diversity characteristics Firms can foster practices that focus on bringing out the full potential of the diversity in their organizations
  • 66. Context Matters For-Profit Organization Good-ole-boy networks can make it difficult for large organizations to embrace diversity Entrepreneurship Families and small businesses often do not have enough employees to truly encourage diversity Nonprofit Organization Focus of the company may influence consideration of diversity Government Sector Differing political views influence government policies