http://www.INE.com

Filtering using AS Path Filters

21

Our Journey

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

• BGP fundamentals

– Injecting networks, iBGP, eBGP, Route

Reflectors, Confederations, Peer Groups

• Policy Based BGP

– Attributes and Filtering

– Manipulating BGP

• Complex Topologies

– Advanced route maps, community, load

balancing, dampening, troubleshooting

Regular expressions

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Application

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

AS Path Access-List

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

AS Path access-list as classifier

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Remove private AS from AS_Path

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Ignore loop prevention of AS_PATH

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Regular expressions in action

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Regular expressions continued

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Regular expressions part 3

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

http://www.INE.com

Route maps

22

When multiple filters exist

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Inject Map

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Conditional Route Injection

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

http://www.INE.com

BGP Communities

23

Change decimal to aa:xx format

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Configure community for outbound updates

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

R1 sees the community sent

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Show BGP table based on community

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

R1 modifies local policy based on

community received

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

AS 11 is now preferring the route

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Agreements between ISPs is the key

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Well known communities

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

http://www.INE.com

Load Balancing

24

BGP Load Balancing

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

iBGP peer R1

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

eBGP peer R6

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Multiple BGP paths

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Global Routing Table

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

http://www.INE.com

Route Dampening

25

Route map for Dampening

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

http://www.INE.com

Working with multiple ISPs

26

Non transit area example.

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Working with multiple ISPs

• Routing

• AS Translation

• Load Sharing

• Remove private AS

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

http://www.INE.com

Scalability

27

Scalability

• Avoid full mesh

– Route Reflectors

– Confederations

• Peer Groups

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

http://www.INE.com

Optimization

28

Optimization

• BGP Convergence

– Scan time

– IGP summarization

• MTU discovery

– Ip tcp path-mtu-discovery

• Peer Groups

• Advertisement Interval

• Prefix limits

• Hold queueCopyright © 2010 Internetwork Expert, Inc

www.INE.com

BGP processes

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Path MTU discovery

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Input Queue

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Modify/Verify input Queue

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

BGP Scan Interval

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

BGP Scan Time

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Configure Max Prefix from peer

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Verify max prefix settings

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

http://www.INE.com

Troubleshooting BGP

29

http://www.INE.com

Course Review

30

Copyright © 2010 Internetwork Expert, Inc

www.INE.com

Thank you for your participation!

• Keith Barker, CCIE #6783• CCIE Routing and Switching – 2001

• CCIE Security – 2003

• kbarker@ine.com

• YouTube - Keith6783