Allowing CARP to use arbitrary OUI prefix and allocating block from FreeBSD's OUI space assignment for that

Eygene Ryabinkin rea at
Thu May 8 10:40:57 UTC 2014

Thu, May 08, 2014 at 10:28:19AM +0000, Bjoern A. Zeeb wrote:
> On 08 May 2014, at 09:50 , Eygene Ryabinkin <rea at> wrote:
> >> Apart from that I thought the different version number was sufficient
> > 
> > The thing is that both VRRP and CARP packets use MAC address (on
> > Ethernet at least) that equals to 00:00:5e:00:01:$VRID.  So in case
> > that $VRID is the same and VRRP and CARP admins aren't aware of each
> > other, there will be MAC conflict, so L2 packets will be switched
> > in a "funny" manner.
> How’s that different routing guys running VRRP on the routers and
> server guys running vrrp on the servers and conflicting on the ID?

Server guys run CARP, not VRRP.  And It Happens (TM).  Cisco-heads
choose VRRP ID of 1 and *BSD-heads take VHID 1 for their CARP.  Bang!

> It’s a management problem in the administrative broadcast domain
> not a CARP vs. VRRP problem.

It hits real networks; moreover, CARP is mostly undocumented stuff
that router admins aren't very much aware of, so this administrative
problem is created by the clashing MAC space that is used by different
protocols.  In a perfect world where everyone knows every possible
bit about protocols it won't happen without poor management.  But the
reality is different, to my regret.
Eygene Ryabinkin                                        ,,,^..^,,,
[ Life's unfair - but root password helps!           | ]
[ 82FE 06BC D497 C0DE 49EC  4FF0 16AF 9EAE 8152 ECFB | ]
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