C I S A | C YB E R S E C U R I T Y A N D I N F R A S T R U C T U R E S E C U R I T Y A G E N C Y
INTRODUCTION TO NETWORK DIAGRAMMING

Notice
Commercial Endorsement Disclaimer: The United States Government through the
Cybersecurity and Infrastructure Security Agency (CISA) of the Department of Homeland Security
(DHS) does not endorse any commercial product or service. Any reference to specific commercial
products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not
constitute or imply their endorsement, recommendation, or favoring by CISA or DHS.
Simulated Non-Production Data Disclaimer: No production data was used in this demonstration.
Sensitive Information Disclaimer: Be aware that this event is live! Events such as these are
attended by people from many different federal agencies. As a student, PLEASE DO NOT
DISCLOSE ANY AGENCY SENSITIVE INFORMATION DURING THIS EVENT.
CISA Comment Policy: This course abides by the CISA Comment Policy (www.cisa.gov/comment-
policy).
DISCLAIMER: This webinar is being recorded and may be made public for the benefit of other
students. While you are encouraged to engage with the speaker, you are advised against
disclosing personally identifiable information (PII) on the recording. Please contact
licensing@cisa.dhs.gov with any questions or comments.
2

1
2 3 4
Agenda
Introduction and
Overview
▪ Learning Objectives
▪ Network Topology
Explained
Topology Basics
▪ Logical vs Physical
▪ Common
Topologies
▪ Network
Architecture
Diagramming Process
▪ Steps
Knowledge Check
▪ Questions
▪ Summary
▪ Resources
3

Course Learning Objectives
Terminal Objective
Enable you to visualize where your network’s physical and logical devices and
connections are by creating or reviewing network topology diagrams.
Enabling Objectives:
▪ Define what a network topology
diagram is
▪ Explain how network topology
diagrams can help organizations
during incident response
▪ Describe the common network
architecture security principles and
designs
▪ Categorize the general steps used
to create network topology
diagrams
Photo source: library.techsmith.com
4

5

Legacy Architecture
6

Modern Architecture
https://www.slideteam.net/0914-complex-networking-diagram-main-office-and-branch-office-wan-lan-and-cloud-ppt-slide.html
7

Incident Response
287days
8
Federal Network Authorization (FNA)
Request for TechnicalAssistance (RTA)

Defining Network Topologies – Logical
Logical
Topology
▪ Abstract
▪ Intangible
parts of the
network
https://www.conceptdraw.com/examples/which-
network-topology-is-used-in-computer-lab
9

Defining Network Topologies – Physical
Physical
Topology
▪ Physical layout
of network
▪ All tangible
assets
https://www.pcwdld.com
10

Topology Types
BUS RING STAR
MESH HYBRID
https://www.pngwing.com
11

Network
Architecture
The complete design and framework
of an organization’s network.
12
https://ipcisco.com/

Asset Discovery and Mapping – Capabilities
https://www.solarwinds.com/
13

Asset Discovery & Mapping – Complex vs Simple
https://www.solarwinds.com
Sample of small network diagram in PowerPoint
14

Data Flow and Storage
Data Flow
The movementof data through a
system composed of
software, hardware, or a combination
of both.
Also known as data-in-transit or
data-in-motion.
https://www.techuseful.com/how-to-protect-data-in-motion-through-managed-file-transer
15

Network Entry and Exit Points
Consider:
▪ Access
authorization
▪ Wired or
Wireless
▪ External
connections
▪ Data transfer
rules
16

Segmented
Networks
17
Helps to limit direct access to
information such as databases,
sensitive information, and
unauthorized applications by a
malicious actor.

Segmentation
Unsegmented Network Segmented Network
https://www.cisa.gov
18

Network Diagramming Process
Maintain
the
Diagram
Create a
Legend
Build the
Diagram
Select a
Network
Template
Choosean
Application
Sketch the
Diagram
Identify
Network
Components
19

Identify
Network
Components
✓ Asset names
✓ Types
✓ Models
✓ IP address
✓ Remote sites
✓ Cloud services
with entry and
exit points
https://www.solarwinds.com
https://www.lansweeper.com
20

Sketch the
Diagram
21

Choose a
Diagramming
Application
22

https://support.microsoft.com
23

Build the
Diagram
▪ Components
denote
physical
entities
▪ Connectors
denote
communication
paths
24

Create a
Legend
Quick and easy
reference to
understand
symbols used
https://www.swotster.com
25

Maintain the
Diagram
26

Knowledge check
27

Summary
✓ Defined what a network topology diagram is
✓ Explained importance of network topology diagrams during
incident response
✓ Described the common network architecture security
principles and designs
✓ Categorized the general steps used to create network
topology diagrams
28

Additional Resources
29
NIST Framework for Improving Critical Infrastructure Cybersecurity
https://nvlpubs.nist.gov/nistpubs/CSWP/NIST.CSWP.04162018.pdf
NIST Special Publication 1800-5 IT Asset Management
https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.1800-5.pdf
CISALayering Network Security Through Segmentation
https://www.cisa.gov/sites/default/files/publications/layering-network-security-
segmentation_infographic_508_0.pdf
Trusted Internet Connections 3.0
https://www.cisa.gov/sites/default/files/publications/CISA%20TIC%203.0%20Reference%20
Architecture%20v1.1.pdf
Computer Security Incident Handling Guide
https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-61r2.pdf
Security and Privacy Controls for Information Systems and Organizations
https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-53r5.pdf

CISAWebsite
https://www.cisa.gov
IR Training Website
https://www.cisa.gov/incident-response-training
CISAGitHub
https://www.cisa.gov/github
CISAYouTube Channel
https://www.youtube.com/channel/UCxyq9roe-npgzrVwbpoAy0A
FedVTE
https://fedvte.usalearning.gov
CISACommenting Policy
https://www.cisa.gov/comment-policy
Additional Resources 2
30

Closing slide