How to prevent asymmetric routing with multiple eBGP routers?
- by Andy Shinn
I have 2 routers announcing a /22 subnet to different providers (one providers connects to each of the 2 routers). I have split the /22 in two /23 to announce one /23 on each of the routers plus the /22 (the providers will take the more specific route). This allows me to fail over and keep traffic inside the /23 in and out the same provider.
What are other ways in which I could announce just the /22 with both routers and have packets from servers on the network behind the routers go back out the same router in which they came in from?
EDIT:
The main problem I come across, which end users and clients complain about the most, is that the least hop route is sometimes not the "optimal" route. In my case, I know that Provider B may have better latency to X nation. But when packets come in from provider B, they may go out Provider A or provider B. The reverse is also true. If I send a packet to X nation out provider A, even though it may have more hops back, the packet will likely come in from Provider B (which may have higher latency, packet loss, etc. to this nation)
