BGP All routes propagate to specific neighbour

[David Kondicz]

How can I configure to propagate all routes from my cisco BGP router to a specific BGP neighbour that is my next router in our datacenter coutes our AS.

All I mean static and dynamically  received from other BGP neighbours.

Thanx

Dave

[sujinair]

Hi David,

By default all BGP prefixes in the BGP table are propagated to neighbor device if no filters are applied except for one condition i.e. routes learned via IBGP are not propagated to other IBGP peers. This is also known as IBGP split horizon and is used to prevent loops.

Regards,

Sujit

[David Kondicz]

Thank you Sujit for answer.

Please see my network diagram:

ISPs < ------- > Peering center <-----------> My Central BGP router (AS 1234 Network 192.168.0.0/24) <---------->  My router in my town (192.168.0.1/25 and 192.168.0.129/25)

Is possible to send BGP routers learned on Cetral BGP router to my router in my town? And if yes, can you please explein me, how to do it? I created Neighbour but on router in my town just receiwing staticli added routes thats are on Central BGP. But i thing this is a default state you wroted.

I want to make a load balancing.

Thanx

Dave

[Kishore Chennupati]

Hi David,

Can you possibly paste in the config of both your Central BGP and Town Router. just the BGP config would do,.

Also, can you please paste in the "sh ip bgp" on both the routers here so that we can take a look and see whats going on.

HTH

Regards

Kishore

[David Kondicz]

I am sorry but i cant.

Central BGP is L3 Cisco switch connected to peering center with gi0/1        default route is received from gi0/2 and backbone link is on gi0/3

Router in twn is no Cisco based.

I receive routes fron gi0/1 , default route from gi0/2 and I want resend this routes to my router in town connected to Gi0/3

[Haris P]

I think this is because of the fact that your ibgp peer doesn't have the route for the bgp-next-hop orthe next hop address is       inaccessible.

Try neighbor {ip-address | peer-group-name} next-hop-self

The next-hop-self command allows you to force BGP to use a specific IP address as the next hop.

Regards

[Kishore Chennupati]

Harish,

The  eBGP routes on the central router should still be advertised to the remote iBGP speaker whether the next-hop-self is configured or not. The iBGP speaker should still be able to get the routes. The  next-hop-self would come into picture when it should install them as  best routes.

HTH

Regards

Kishore

[Haris P]

Kishore ,

What you are saying is absolutely correct . The ebgp willl be there in the bgp table ,but next-hop-self will only help to install them in the routing table

As sujith said by dafault all routes are passed to neighbor. Only condition is that your peering center is not in the same AS (AS 1234) . If it is in same AS  you may need to create an IBGP session between your router in town and peering center router

Regards

Haris

[David Kondicz]

Thank you!

I made it with setting up route-reflection-client on neighbour setting in iBGP!

BR

Dave