I posted PR misc/23431 (should have been kernel?) for experimental CARP 
support for -current.  (only tested on i386 -current)

The OpenBSD man page for CARP just about sucks right now, so I put my 
own documentation in the PR.  Here's a link to the man page anyway:
http://www.openbsd.org/cgi-bin/man.cgi?query=carp&apropos=0&sektion=4&manpath=OpenBSD+Current&arch=i386&format=html

The impatient can download the patches from 
ftp://63.251.83.132/pub/NetBSD/patches/carp-111303.diff
You'll have to add the following to your kernel config file:

pseudo-device   carp   2
options   CARP

You may or may not also want to change vrrp to carp in 
/etc/protocols...  OpenBSD pretty much replaced all references to VRRP 
with CARP.  My patches, like OpenBSD's implementation, use 224.0.0.18 
and protocol id 112 for advertisements (same as VRRP).  The vhid is in 
the same location as VRRP's vrid in the advertisement.  Since there are 
256 id's to choose from, you should'nt have any problem using CARP and 
VRRP on the same LAN.



There's still a lot to do, this is just enough to get started.  The rest 
of the details are in the PR.

~Mike.