Loop backs as BGP Neighbors

adriansizemore

I was having some issues bringing up bgp neighbors on my two CE routers. I looked at the RD info on the PE's, and they were receiving bgp updates for the CE routers. However, I was not able to get the LBs on my CE routers to become BGP neighbors.

I had to redistrubute connected and configure a BGP neighbor. Is this the right way to do it, or is there a better, more appropriate way?

Configs:

CE (CU1)
router bgp 65101
bgp log-neighbor-changes
neighbor 12.0.0.3 remote-as 65102
neighbor 12.0.0.3 ebgp-multihop 254
neighbor 12.0.0.3 update-source Loopback0
neighbor 172.16.1.2 remote-as 65400
!
address-family ipv4
redistribute connected
redistribute static
neighbor 12.0.0.3 activate
neighbor 172.16.1.2 activate
no auto-summary
no synchronization
network 12.0.0.1
exit-address-family
!
ip route 0.0.0.0 0.0.0.0 172.16.1.2
!

cu1#show ip route
Gateway of last resort is 172.16.1.2 to network 0.0.0.0
172.16.0.0/30 is subnetted, 2 subnet
B 172.16.1.4 [20/0] via 172.16.1.2, 00:11:49
C 172.16.1.0 is directly connected, FastEthernet0/0
12.0.0.0/32 is subnetted, 2 subnets
C 12.0.0.1 is directly connected, Loopback0
B 12.0.0.3 [20/0] via 12.0.0.3, 00:00:00
S* 0.0.0.0/0 [1/0] via 172.16.1.2
cu1#
cu1#sho ip bgp
BGP table version is 50, local router ID is 12.0.0.1
Network Next Hop Metric LocPrf Weight Path
*> 12.0.0.1/32 0.0.0.0 0 32768 ?
*> 12.0.0.3/32 12.0.0.3 0 0 65102 ?
* 172.16.1.2 0 65400 65102 ?
* 172.16.1.0/30 12.0.0.3 0 65102 65400 ?
*> 0.0.0.0 0 32768 ?
* 172.16.1.2 0 0 65400 ?
* 172.16.1.4/30 12.0.0.3 0 0 65102 ?
*> 172.16.1.2 0 65400 ?


CE (CU1A)
router bgp 65102
bgp log-neighbor-changes
neighbor 12.0.0.1 remote-as 65101
neighbor 12.0.0.1 ebgp-multihop 254
neighbor 12.0.0.1 update-source Loopback0
neighbor 172.16.1.6 remote-as 65400
!
address-family ipv4
redistribute connected
redistribute static
neighbor 12.0.0.1 activate
neighbor 172.16.1.6 activate
no auto-summary
no synchronization
network 12.0.0.3
exit-address-family
!
ip route 0.0.0.0 0.0.0.0 172.16.1.6

cu1a#show ip route
Gateway of last resort is 172.16.1.6 to network 0.0.0.0
172.16.0.0/30 is subnetted, 2 subnets
C 172.16.1.4 is directly connected, FastEthernet0/1
B 172.16.1.0 [20/0] via 172.16.1.6, 00:43:24
12.0.0.0/32 is subnetted, 2 subnets
B 12.0.0.1 [20/0] via 12.0.0.1, 00:00:00
C 12.0.0.3 is directly connected, Loopback0
S* 0.0.0.0/0 [1/0] via 172.16.1.6

cu1a#sh ip bgp
BGP table version is 95, local router ID is 12.0.0.3
Network Next Hop Metric LocPrf Weight Path
*> 12.0.0.1/32 12.0.0.1 0 0 65101 ?
* 172.16.1.6 0 65400 65101 ?
*> 12.0.0.3/32 0.0.0.0 0 32768 ?
* 172.16.1.0/30 12.0.0.1 0 0 65101 ?
*> 172.16.1.6 0 65400 ?
* 172.16.1.4/30 12.0.0.1 0 65101 65400 ?
*> 0.0.0.0 0 32768 ?
* 172.16.1.6 0 0 65400 ?
cu1a#

rossonieri#1

hi adrian,

you mean you cant make them peers between 2 routers CE-PE?
have you created a static route on both pointing their loopback?

ps :

redistribute connected has a slight effect being redistributing all unnecessary route that CE shouldnt know about, so better to distribute it carefully - especially when you are also redistributing IGP to BGP.

and that is very huge lab you have there,
how many machines involved? how much RAM?