How do I connect to a eBGP Peer with the same AS number?

[scottrichmond]

I need to establish a eBGP peer relationship with a third party peer using private BGP AS numbers. Unfortunately their using the same BGP AS number as we are. Is there any way to work around this problem without having one side change their BGP number? Are BGP Confederations a solution?

[Steven Williams]

That would be an iBGP peering. eBGP peers require different AS numbers.

[milan.kulik]

Hi,

possibly on one side

neighbor x.x.x.x remote-as 65010

neighbor x.x.x.x local-as 65011 no-prepend replace-as

and on the other side

neighbor y.y.y.y remote-as 65011

neighbor y.y.y.y local-as 65010 no-prepend replace-as

?

I never tested though.

Are you sure the third party is using just one private AS number?

If not, there might be other AS numbers in clash with your ones and some prefixes get lost.

Best regards,

Milan