Re: how to effectively use multiple gateways?

Steve Thompson wrote:

Systems a1, a2 and a3 are three systems have interfaces on both 192.168.0/22 and 192.168.4/22 (not the actual values). Systems a4 and a5 (actually many systems) are connected only to 192.168.0/22. Systems b1, b2 and b3 (several dozens of these) are connected only to 192.168.4/22 via a single interface each.

How would you establish the default gateway for b1, b2, ..., given that a1, a2 and a3 can do NAT on behalf of the b's. I'd like to take advantage of the fact that there are three possible default gateways for the b's to give some redundancy if a1 (say) is shut down (no manual intervention).
three default gateways? routed? gated?

Redundant routers with Linux and Keepalived
http://tips.linux.com/tips/05/05/10/1436254.shtml?tid=100
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