Table of Contents
Border Gateway Protocol (BGP4)
Border Gateway Protocol (BGP)
BGP Part 1
Routing versus Forwarding
IP Routing
IP Routing
IP routing
IP route lookup
IP route lookup: Longest match routing
IP route lookup: Longest match routing
IP route lookup: Longest match routing
IP route lookup: Longest match routing
IP route lookup: Longest match routing
Dynamic Routing
Forwarding Table/FIB
Routing Tables Feed the Forwarding Table
Building Blocks
Autonomous System (AS)
Autonomous System (AS)...
Routing flow and packet flow
Egress Traffic
Ingress Traffic
Types of Routes
What is Policy?
Interior vs. Exterior Routing Protocols
Hierarchy of Routing Protocols
DeMarcation Zone (DMZ)
Addressing – ISP
BGP Part 2
BGP Basics
Protocol Basics
Protocol Basics
Terminology
Terminology
BGP Basics …
BGP Peers
BGP Peers
BGP Peers
Configuring BGP Peers
Configuring BGP peers
Configuring BGP peers
Configuring BGP peers
Configuring BGP peers
Configuring BGP peers
Configuring BGP peers
BGP Update Messages
BGP Updates — NLRI
BGP Updates — Attributes
AS-Path Attribute
Next Hop Attribute
Next Hop Attribute
Next Hop Attribute
Next Hop Attribute (more)
BGP Updates – Withdrawn Routes
BGP Updates – Withdrawn Routes
BGP Routing Information Base
BGP Routing Information Base
BGP Routing Information Base
BGP Routing Information Base
BGP Routing Information Base
BGP Routing Information Base
An Example…
BGP Part 3
Basic BGP commands
Inserting prefixes into BGP
“redistribute static”
“redistribute static”
“network” command
Aggregates and Null0
Stable iBGP peering
BGP Part 4
BGP Path Attributes: Why ?
BGP Path Attributes...
AS-PATH
AS-Path
Next-Hop
Third Party Next Hop
Next Hop...
Local Preference
Local Preference
Multi-Exit Discriminator
Multi-Exit Discriminator (MED)
Origin
Communities
Communities
Weight
Administrative Distance
Synchronization
Synchronization
BGP route selection (bestpath)
BGP route selection (bestpath)
BGP route selection (bestpath)
BGP Route Selection...
BGP Part 5
PPT Slide
Filter list rules Regular Expressions
Filter list – using as-path access list
Policy Control – Prefix Lists
Prefix Lists – Examples
Prefix Lists – More Examples
Policy Control Using Prefix Lists
Policy Control – Route Maps
Route-map match & set clauses
Route Map: Example One
Route Map: Example Two
BGP Part 6
PPT Slide
Stub AS
PPT Slide
Multi-homed AS
Service Provider Network
Common Service Provider Network
Load-sharing – single path
Load-sharing – multiple paths from the same AS
Redundancy – Multi-homing
Default from all providers
Default from all providers
Customer prefixes plus default from all providers
Customer routes from all providers
Full routes from all providers
Full routes from all providers
Best Practices IGP in Backbone
Best Practices... Connecting to a customer
Best Practices... Connecting to other ISPs
Best Practices... The Internet Exchange
Summary
|