BGP multihoming with Redundant routers

[Shaikh Aman Uddin]

Hi,

I have two perimeter routers connected with two different ISPs . I have my own BGP AS number and public ip pool. I want to run BGP Multihoming with redundant routers. so that I can load balance my inernal traffic with two different ISPs. Kindly share your advise.

Thanks,

Aman

[George Horton]

I am assuming that you want to load balance the links in both inbound and outbound directions.

Inbound load balancing is all down to how you advertise your own routes.  if the ISP's allo you can split the subnet and use AS-path prepend to have one ISP preferred for one half of the subnet and the other ISP for the other half.  If the ISP's are not happy with that then you are stuck with letting BGP decide the best path from the remote source to your network.

Outbound load balancing can be done with filtering the routes from the ISP, however I suggest not connecting the routers with iBGP, have one router connected to each ISP, and then run something like GLBP between the routers.