two bgp as

[MARCELO MATURO]

Is it possible to have two different BGP AS in the same router?

Thank's

Marcelo

[paolo bevilacqua]

Yes, in a kind of virtual manner. That is because you can manipulate AS numbers in any way you want.

[MARCELO MATURO]

Thank's

Can you tell me some link with an example?

Marcelo

[paolo bevilacqua]

Are you familiar with BGP configuration and AS path manipulation ? All that is documented in the cisco manuals.

That is the pre-requisite for what you want to do.

[Harold Ritter]

Marcelo,

You might want to check the following example.

http://www.cisco.com/en/US/docs/ios/12_4t/ip_route/configuration/guide/brbpeer.html#wp1126960

Regards,

[MARCELO MATURO]

I applied this configuration but I can't get the peering. There is the following error:

Jun 11 10:38:04: %BGP-3-NOTIFICATION: sent to neighbor 77.1.248.25 3/11 (invalid or corrupt AS path) 3 bytes 400200

[Harold Ritter]

Marcelo,

Can you send a bit more info about the topology and configuration that you are trying to implement.

Regards,

[MARCELO MATURO]

This is the configuration. I need peering with 2 differente AS. The AS 65200 see me as 65200 y de 11664 see me as 65194.

!

router bgp 65194

no synchronization

bgp log-neighbor-changes

redistribute connected

neighbor 77.1.248.25 remote-as 65200

neighbor 77.1.248.25 local-as 65200 no-prepend replace-as

neighbor 154.0.17.129 remote-as 11664

neighbor 154.0.17.129 send-community

no auto-summary

!

[Harold Ritter · Accepted solution]

Marcelo,

You cannot use this command on an iBGP peer. You can inverse the logic though, change your "router bgp" ASN to 65200 and use the local-as command on the peer to ASN 11664 instead as follow:

router bgp 65200

neighbor 77.1.248.25 remote-as 65200

neighbor 154.0.17.129 remote-as 11664

neighbor 154.0.17.129 local-as 65194 no-prepend replace-as

Regards,

[MARCELO MATURO]

Thank's Hritter. Your answer resolved my issue.

Marcelo

[Harold Ritter]

Marcelo,

You can only assign one AS number to your BGP router process but you can change that AS number when you connect to BGP peers by using the local-as feature.

Regards,