I am currently trying to use two m0n0wall boxes to eliminate the risk of
downtime due to hardware failure on a single box. Each machine now acts as
a gateway and DHCP server, serving IP's from two different IP ranges
within the same subnet.
Everything seems to be working fine with this setup. However, I'd really
like to make DHCPD on both machines provide clients with two gateway
adresses, that is the adress of each machine. Apparently windows can
accept a primary and a secondary gateway address, and automatically try
the other if one fails.
As far as I can see this would provide me with a complete failover in case
one machine fails. As of now, the client would have to get a new DHCP
lease, to switch to another gateway, which is not optimal.
I'm doing this for a small institution where I'm only working part time,
so I can't just keep a backup machine handy to replace a failing machine.
Is there any way of making m0n0wall provide clients with two gateway
adresses?

Also can anybody see any weaknesses in this setup?

Regards,
Tor Bechmann Sorensen