verifying BGP loadbalancing

[fawad.alam]

I have two BGP routers in AS 10 peering with two BGP routers in AS20. I have to load balance inbound traffic for network 10.10.10.x in AS 10 on the two links for users accessing from AS20. I think the best & easiest way to achieve this is to use MED on AS10 routers and advertise this network to AS20 routers with the same MED. Any comments?

The key point is how to verify that the inbound traffic is really load balanced with equal link utilization.

Any suggestion would be appreciated.

[amarsjoshi]

This would largely depend upon how AS20 is configured beyond the routers that you are connected to..

Assume, this is the setup on AS20

...RTRA......RTRB

..RTRC...

Where RTRC is the internal IBGP router for AS20 with links to RTRA and RTRB. IF RTRC has IBGP max-paths configured then all traffic to A and B would be load balanced, which you would see on your side..

Your MED will not make a difference as long as they are equal, even if you send the default to them, it all depends upon what path they use to get to you and how they are configured internally..

HTH,

Amar

[smothuku]

Hi ,

check out the below link for loadbalancing using MED.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094934.shtml

Thanks,

satish