Dual ISP Configuration Question?

j-nagy · ‎03-31-2008

I am looking at how to best provide load sharing for my company's 2 Internet connections located at two physical locations. I inherited this topology and need to make it work with minimal $$$. We will be looking to acquire our own public IP block and eventually use a L2 solution between the sites - for now this is what I am working with.

*HQ is Site#1

*DR Hot site is Site#2

*Each site has a different block of IPs provided from ISPs

*Each site sits on a different LAN

*Each site currently peers with its respective ISP

*Both sites have a 50MB Internet link from two different ISPs

*My company does have a registered AS# and each sites peers with it's respective ISP

*3825 has upgraded memory to handle the BGP tables

*The two sites are connected via a point-to-point OC3

Diagram is below - hope the format comes out in the post:

7206_L3---CPE_3845_Site#2---50MB_ISP#2

|

7206_L3---CPE_3825_Site#1---50MB_ISP#1

Is what I am trying to accomplish even possible with what I have?

Can I request the two ISPs peer with each other?

paolo bevilacqua · ‎03-31-2008

Seem to me you've enough. You don't ask your ISPs to peer with each other, you do peer with both using your own AS. Then your addresses become reachable from both ISPs.

If you have never done multihoming BGP, suggest you get advice from someone that knows about (proven experience) to get "sure results" at the first try. After that it becomes a matter of maintenance, monitoring and tuning.

Hope this helps, please rate post if it does!