BGP

[AshokJat]

Hi,

I am configuring ebgp, one side i have AS 100 and another side I have AS 200,  when I am unable to make them neighbor

what can be the reason.

Thanks

Ashok 

[MHM Cisco World]

is the neighbor is direct connect or you use loopback ? if you use loopback then check the reachability and if it reachable it may need to enter ebgp multi hop  command.

[Flavio Miranda]

Hi

 There are thousand reasons.  Be more specific and you can be helped.  First step is reachiability as mentioned in the other answer. But does not stop there.

 BGP is a layer 4 connection  between nodes on TCP port 179. It does not required direct connection but if you are a few hops away you may need ajust ebgp multi hop as mentioned.

  Start with that and post your progress. You can also share the command "show run | sec router bgp" in order to speed up things.

[AshokJat]

Hi,

I have direct connected nodes but in different AS, and not using any loopback address there

[Georg Pauwen]

Hello,

post the running configs of both routers.

[paul driver]

Hello

Do you have ip connectivity between the rtrs?

if your peering on loopbacks then do the rtrs have knowledge how to reach those loopbacks and at least on side needs to peer with neighbour xxx  update- source loopback x and disable-check-connected or ebgp-multihop 

Do NOT use default routes to try and establish peering use either static or dynamic igp routing for reachability 

[Richard Burts]

As mentioned by others we need more information to be able to understand the issues and to give good advice. It would be nice to see the complete current running config of both. But if you do not want to post complete configs it would help if you post the interface configs and the bgp config.

[AshokJat]

Hi @Richard Burts 

Thanks for response, actually I found where was issue, it was hold timers issue..

[Richard Burts]

Ashok

Thanks for the update. Glad that you have been able to find the problem and solve it. Thanks for sharing this with the community.