A power supply failed in my 2-node OpenBSD 5.1 unicast CARP cluster recently. After the failure I noticed that the carp demote counter was being increased by output errors:
carp: carp0 demoted group carp by 1 to 1 (> snderrors) I tracked this back to the surviving node being unable to arp for the ethernet address of its carppeer. At least, adding static permanent arp entries stopped the Oerrs on carp0. I'm planning on adding static arp entries as a best-practice now any time I use unicast CARP. I didn't see any documentation or list traffic on this topic, though, so I thought I'd ask what others do. Am I missing something or is this ill-advised? Thanks, -lee