Loopback interface is not working with BGP

[turbo_engine26]

Hello,

I configured Loopback0 interfaces on EBGP peers as shown below.

R1(config)#interface loopback 0

R1(config-if)#ip address 10.50.250.1 255.255.255.255

R1(config)#router bgp 50

R1(config-router)#neighbor 10.100.83.1 remote-as 100

R1(config-router)#neighbor 10.100.83.1 ebgp-multihop 2

R1(config-router)#neighbor 10.100.83.1 update-source loopback 0

R1(config)#ip route 10.100.83.1 255.255.255.255 serial 1/0

R2(config)#interface loopback 0

R2(config-if)#ip address 10.100.83.1 255.255.255.255

R2(config)#router bgp 100

R2(config-router)#neighbor 10.50.250.1 remote-as 50

R2(config-router)#neighbor 10.50.250.1ebgp-multihop 2

R2(config-router)#neighbor 10.50.250.1 update-source loopback 0

R2(config)#ip route 10.50.250.1 255.255.255.255 serial 1/0

However, i can't ping both loopback interfaces and no BGP connection established.

Appreciate your cooperation.

Regards,

A.M.

[Marwan ALshawi · Accepted solution]

First can you ping the next hop ip configured on the serial interfaces ? If yes then use the next hop ip configured in serial interface in the static route rather than using interface serial

And try to ping loopbacks sourcing the ping from the local loopback

Ping x.x.x.x source interface loopback0

Hope this help

Sent from Cisco Technical Support iPhone App

[turbo_engine26]

There are no ip addresses configured in the serial interfaces. Just the loopbacks.

[Marwan ALshawi]

thats why it is not working

you need to have IPs in the serial interfaces and ping each other first

[turbo_engine26]

Marwan,

You solved the problem thx and sorry for the late repy. The case study that i am currently working on didn't mention any serial interfaces to be configured because the topic is about loopback interfaces only, therefore the author ommitted the use of serial interfaces in the case study.

Thx again.

HTH

A.M.

[Kishore Chennupati]

Hi Turbo,

You first need to establish NLRI and then check for BGP. Unless you have end to end layer 3 connectivity BGP won't work. As marwan pointed out you need to fist have IP's on the serial interfaces. If you are trying to do the same on a L3 switch then its different. You can have SVI's and have a trunk between the swithces and can peer on the vlan interfaces. In that case you dont need to confgure IP addresses on the trunks.

HTH

Thanks

Kishore