Re: Simultaneous CARP failover for multiple interfaces

Kyle Lanclos <[email protected]> Fri, 27 Apr 2012 11:05:47 -0700
Newsgroups gmane.os.openbsd.pf
Message-ID <[email protected]>
I quoted from the OpenBSD FAQ:
> net.inet.carp.preempt		Allow hosts within a redundancy group
> 				that have a better advbase and advskew
> 				to preempt the master. In addition, this
> 				option also enables failing over a group
> 				of interfaces together in the event that
> 				one interface goes down. If one physical
> 				CARP-enabled interface goes down, CARP
> 				will increase the demotion counter,
> 				carpdemote, by 1 on interface groups that
> 				the carp(4) interface is a member of, in
> 				effect causing all group members to fail-
> 				over together. 
> 
> I did establish an interface group for my two CARP interfaces, but I did
> not do my failover tests while it was in that state. As I said, I clearly
> need to re-do my tests.

I re-did my tests this morning, and yes indeed, both CARP interfaces in
the CARP group switch automatically between the BACKUP and MASTER states
when I do abusive things to one of the connections. I say "automatically"
instead of "simultaneously" because there was a bit of a delay while the
reconnected link negotiated speed. I blame Cisco for that.

Thanks for all the assistance, I found this exchange to be quite helpful.

--Kyle