summary: gateway failover.

first of all, sorry for the duplicate message. i originally
sent it without my proper from address to avoid having my
primary mailbox spammed, but thought it wouldnt go through
because the from address wasnt on nanog-post...

second, i incorrectly referred to the rfc for IRDP as 1285,
when it is 1256.

re: IRDP support. the following os's/routing daemons have support:

gated (version ?)
Solaris (in.rdisc(1))
Windows NT (with sp3)
Windows 95 (with Sockets 2)

a couple of useful urls were sent my way, the most interesting

which details an Open Source HA project by Ericsson (very cool),
which is unfortunately only supported under Linux for the time
being, though Solaris/FreeBSD support is slated for December.

another from a usenix/lisa presentation with some good info is here:

also, many suggestions were given for ways to accomplish this
goal with network layer stuff (ospf, rip, interface aliases,
proxy arp, etc.), though i was looking for an application layer
solution, primarily. if you'd like details on the various
suggestions, email me privately.