Webinar topic: BGP Services IP Transit vs IP Peering Presenter: Achmad Mardiansyah In this webinar series, We are discussing BGP Services IP Transit vs IP Peering Please share your feedback or webinar ideas here: http://bit.ly/glcfeedback Check our schedule for future events: https://www.glcnetworks.com/en/schedule/ Follow our social media for updates: Facebook, Instagram, YouTube Channel, and telegram Recording available on Youtube https://youtu.be/TYNHBSTxiOE

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BGP services:
IP transit
vs
IP peering
GLC webinar, 12 Aug 2021
Achmad Mardiansyah
achmad@glcnetworks.com
GLC Networks, Indonesia
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Agenda
● Introduction
● Review prerequisite knowledge
● IP services
● IP transit vs IP peering
● Live practice
● Q & A
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introduction
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What is GLC?
● Garda Lintas Cakrawala (www.glcnetworks.com)
● Based in Bandung, Indonesia
● Areas: Training, IT Consulting
● Certified partner for: Mikrotik, Ubiquity, Linux foundation
● Product: GLC radius manager
● Regular event
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Trainer Introduction
● Name: Achmad Mardiansyah
● Base: bandung, Indonesia
● Linux user since 1999, mikrotik user since 2007, UBNT
2011
● Mikrotik Certified Trainer
(MTCNA/RE/WE/UME/INE/TCE/IPv6)
● Mikrotik/Linux Certified Consultant
● Website contributor: achmadjournal.com, mikrotik.tips,
asysadmin.tips
● More info:
http://au.linkedin.com/in/achmadmardiansyah
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Past experience
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● 2021 (Congo DRC, Malaysia): network support,
radius/billing integration
● 2020 (Congo DRC, Malaysia): IOT integration,
network automation
● 2019, Congo (DRC): build a wireless ISP from
ground-up
● 2018, Malaysia: network revamp, develop billing
solution and integration, setup dynamic routing
● 2017, Libya (north africa): remote wireless migration
for a new Wireless ISP
● 2016, United Kingdom: workshop for wireless ISP,
migrating a bridged to routed network

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About GLC webinar?
● First webinar: january 1, 2010 (title:
tahun baru bersama solaris - new year
with solaris OS)
● As a sharing event with various topics:
linux, networking, wireless, database,
programming, etc
● Regular schedule
● Irregular schedule: as needed
● Checking schedule:
http://www.glcnetworks.com/schedule
● You are invited to be a presenter
○ No need to be an expert
○ This is a forum for sharing: knowledge,
experiences, information
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Please introduce yourself
● Your name
● Your company/university?
● Your networking experience?
● Your mikrotik experience?
● Your expectation from this course?
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Prerequisite
● This presentation some prerequisite knowledge
● We assume you already know:
○ How networking works
○ Able to setup a simple network
○ Familiar network devices
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Review prerequisite knowledge
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How Internet works
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A bit of history...
● Initially, research project (’70-’80s) – Open, cooperative, public domain
○ “Rough consensus and running code”
● Then, product of liberalisation (’90s) – Also, catalyst for deregulation
○ Commercial, competitive environment
● Now, public utility and critical infrastructure (since 2000 and beyond)
○ “Internet governance” is a recent afterthought
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Source: APNIC

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Before internet...
● Computer networking already exist… but many are proprietary
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Source: APNIC

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We need standards
● Standards operate at different levels of the network “stack”
○ in fact they define the stack
● A standard (or protocol) is simply an agreement
○ among members of a community,
○ on a set of guidelines or rules,
○ which allow cooperation (interoperability),
○ sometimes, in a forum such as ISO, ITU, W3C or IETF.
● An open standard is a standard which is
○ Developed through open and accessible processes
○ Freely accessible, implementable and usable
○ Available without barriers such as licenses and fees.
○ ... “ideally”, at least.
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Source: APNIC

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Internet defines a standard for communication
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Source: APNIC

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After internet...
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Source: APNIC

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Why use internet
● Open
○ Free standards and implementations – Low barrier to entry
● Lightweight
○ “Dumb”: simple and efficient
○ Intelligence at the edges: in applications and devices
● Global
○ Uniform, “End-to-End”
● Neutral
○ By default
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Source: APNIC

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Layers in telecommunincations
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Source: APNIC

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Layers in communication (traditional vs internet)
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Source: APNIC

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7 OSI layer & protocol
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● OSI layer Is a conceptual model from ISO
(International Standard Organization) for project
OSI (Open System Interconnection)
● When you send a message with a courier, you
need to add more info to get your message arrived
at the destination (This process is called
encapsulation)
● What is protocol
○ Is a set of rules for communication
○ Available on each layer
● Communication consist of series encapsulation
○ SDU: service data unit (before PDU)
○ PDU: protocol data unit (after header is added)

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Layered model (TCP/IP vs ISO) and encapsulation
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/ datagram

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Internet addressing
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Addressing, IANA, RIR
● Internet is based on IP (internet protocol) addressing scheme -> RFC791
● Addressing has to be unique.
● We need an international body that regulates IP addressing -> IANA (Internet
Assigned Number Authority)
● IANA delegates (some of its authority) to RIR (Regional Internet Registry)
● RIR delegates to country’s
● Every organisation must have IP address block and Autonomous System
Number to join the internet and build a routing scheme among their
equipment
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Autonomous System (AS)
● Collection of networks with same routing policy
● Single routing protocol
● Usually under single ownership, trust and administrative control
● Identified by a unique 32-bit integer (ASN)
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source: philip smith,
introduction to BGP

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Computer network topology
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HUB, switch, router, firewall
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Router and Routing
● Router is a network device that is used to forward packets, based on layer 3
information (layer 3 header)
● Routing is the process of selecting a path for traffic in a network, or between
or across multiple networks
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Physical
router
Router
icon

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Typical connection (physical)
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R2
R1
R3
● Router connects layer 2
segments
● Router works on layer 3
● Meaning, each layer 2
segment has network ID

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Typical connection (logical) and routing table
Routing table:
● A table at router that is used to forward packet
● Available on every devices (router and host)
● Entry is executed sequentially
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192.168.0.0/26
R1
192.168.0.1/26
192.168.0.3/26
192.168.0.2/26
R3
R2
192.168.1.0/24
192.168.2.0/24
192.168.3.0/24
192.168.3.3/24
192.168.3.9/24
192.168.2.9/24
192.168.2.2/24
192.168.1.1/24
192.168.1.9/24
destination gateway
192.168.0.0/26 direct
192.168.1.0/24 direct
192.168.2.0/24 192.168.0.2
192.168.3.0/24 192.168.0.3
192.168.16.3/32 192.168.0.2
0.0.0.0/0 (default gw) 192.168.0.3

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Internet topology
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Inter-connected networks
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Source: APNIC

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Your ISP and you
● ISP is an organisation that is part of internet that provides connectivity to their
customers
○ Identified by their AS (Autonomous System) number
○ Identified by their IP address block
● When you connect to internet, you will use your ISP’s address
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Your ISP. and you
are part of them
other
ISP
other
ISP
google
facebook
Your house

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At your ISP (physical connection)
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Border
router
Other
ISP
Other
ISP
Access
router
Access
router
customer customer customer
Access network: GPON, WLAN,
FO, GSM, ethernet, etc
Clouds of
routers

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Border Gateway Protocol (BGP)
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What is BGP features?
● Path Vector Protocol
● Incremental Updates
● Many options for policy enforcement
● Support VLSM
● Classless Inter Domain Routing (CIDR)
● Widely used for Internet backbone
● Connects Autonomous systems
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What is VLSM?
● Variable-Length Subnet Masking (VLSM)
● Can divide an IP address block into subnets of different sizes using / (slash)
notation
● Solution the in efficient of classful IP address (fixed length). No more class A,
class B, Class C -> please don't say these classes anymore
● making it possible to create subnets with very different host counts without
wasting large numbers of addresses.
● RFC: 1878 (1995)
● Basis for CIDR
● Example: 23.45.0.0/16
○ 23.45.0.0/25
○ 23.45.0.128/25
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VLSM RFC
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What is CIDR?
● CIDR: Classless Inter-Domain Routing (sometimes is called supernetting)
● CIDR solves problem of wasted address space by providing a new and more
flexible way to specify network addresses in routers (using slash as notation)
● allow flexible allocation of Internet Protocol (IP) addresses.
● Replaces classful network (class A,B,C,D). Please don't ever mention this
anymore...
● CIDR lets a routing table entry represent an aggregation of networks that exist
in the forward path
● Each IP address has a network prefix that identifies either one or several
network gateways.
● RFC: 1519
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CIDR
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Path Vector Protocol
● BGP is classified as a path vector routing protocol (see RFC 1322)
● A path vector protocol defines a route as a pairing between a destination and
the attributes of the path to that destination.
● See AS path below
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Path vector protocol
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Image source: philip smith,
introduction to BGP

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BGP connectivity (aka. peering)
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source: philip smith,
introduction to BGP

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Building forwarding table for BGP
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source: philip smith,
introduction to BGP

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eBGP vs iBGP
● BGP is used
○ Internally, inside AS (iBGP - internal BGP)
○ Externally, between AS (eBGP - external BGP)
● iBGP is used to carry
○ Some/all Internet prefixes across ISP backbone
○ Prefixes from ISP customers
● eBGP is used to
○ Exchange prefixes with other ASes
○ Implement routing policy
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eBGP & iBGP
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source: philip smith,
introduction to BGP
IGP: interior Gateway Protocol.
E.g. RIP, OSPF, IEGRP

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External BGP Peering (eBGP)
● Between BGP speakers in different AS
● Should be directly connected
● Never run an IGP between eBGP peers
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source: philip smith,
introduction to BGP

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Internal BGP (iBGP)
● BGP peer within the same AS
● Not required to be directly connected
○ IGP takes care of inter-BGP speaker connectivity
● iBGP speakers must be fully meshed:
○ They originate connected networks
○ They pass on prefixes learned from outside the ASN
○ They do not pass on prefixes learned from other iBGP speakers
● Recommended to do peer with loopback interface
● To avoid mesh peering: AS confederation, route reflector
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source: philip smith,
introduction to BGP

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BGP connectivity
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Peering types
● Transit - service provided by an ISP to carry other ISP/customer traffic to
other network (internet). Usually is for commercial (paid service)
● Peering - 2 ISPs or more exchange traffic and routing information. Can be
commercial or non commercial (gratis). Example: peering on IXP (Internet
Exchange Point)
● Default - default route, sending traffic to default router of there is no explicit
match on routing table
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IP peering example
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IP transit example
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Border
router
Other
ISP
Other
ISP
Access
router
Access
router
Ordinary
customer
Customer
with AS
number
customer
Access network: GPON, WLAN,
FO, GSM, ethernet, etc
Clouds of
routers

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Peering and transit example (IIX vs openIXP?)
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source: philip smith,
introduction to BGP

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LIVE practice
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preparation
● SSH client
● SSH parameters
○ SSH address
○ SSH port
○ SSH username
○ SSH password
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Q & A
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Interested? Just come to our training...
● Topics are arranged in systematic and logical way
● You will learn from experienced teacher
● Not only learn the materials, but also sharing experiences, best-practices, and
networking
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End of slides
● Thank you for your attention
● Please submit your feedback: http://bit.ly/glcfeedback
● Find our further event on our website : https://www.glcnetworks.com/en/
● Like our facebook page: https://www.facebook.com/glcnetworks
● Slide: https://www.slideshare.net/glcnetworks/
● Recording (youtube): https://www.youtube.com/c/GLCNetworks
● Stay tune with our schedule
● Any questions?
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