BGP confederations.

Building on the lab i posted last i have been configuring iBGP and eBGP, following its paths and debugging and fixing best paths and typo’s i made when setting the lab up. It proves how hands on is very important and getting dirty with BGP has really helped. This week i also ran route reflectors, and tonight add to this confederations. Here is the lab now with the AS numbers and the confederation AS numbers.

The running config is on each router. (i have a eBGP config on router 6 to router 2, not shown below)

Router 1
router bgp 65001
neighbor 172.106.21.2 remote-as 65001
neighbor 172.106.21.2 route-reflector-client
neighbor 172.106.41.4 remote-as 65001
neighbor 172.106.41.4 route-reflector-client
neighbor 172.106.31.3 remote-as 65002
bgp confederation peer 65002
bgp confederation identifer 200
no synchronization
bgp log-neighbor-changes

Router 2

router bgp 65001
no synchronization
bgp log-neighbor-changes
neighbor 172.106.21.1 remote-as 65001
neighbor 172.106.26.6 remote-as 600
bgp confederation identifer 200
no auto-summary

Router 3

router bgp 65002
no synchronization
bgp log-neighbor-changes
neighbor 172.106.31.1 remote-as 65001
neighbor 172.106.35.5 remote-as 65002
bgp confederation peer 65001
bgp confederation identifer 200
no auto-summary

Router 4

router bgp 65001
no synchronization
bgp log-neighbor-changes
neighbor 172.106.41.1 remote-as 65001
no auto-summary

Router 5
router bgp 65002
no synchronization
bgp log-neighbor-changes
neighbor 172.106.35.3 remote-as 65002
no auto-summary

To see this working as it should be on router 3,

ROUTER_3#sh ip
BGP table version is 4, local router ID is 172.106.35.3
Status codes: s suppressed, d damped, h history, * valid, > best, i – internal,
r RIB-failure, S Stale
Origin codes: i – IGP, e – EGP, ? – incomplete

Network Next Hop Metric LocPrf Weight Path
*> 172.106.106.0/24 172.106.26.6 0 100 0 (65001) 600 i

You can see that router three has leant of router six’s loop back address from AS 65001, the brackets mean that it was learned by a confederation. Nice.

BE

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~ by bigevil on June 11, 2010.

 
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