On Wed, Apr 05, 2006 at 03:16:04PM -0700, Gustavo A. Baratto wrote:
> Greetings all...
>
> We were trying to upgrade a couple of boxes (fw1 and fw2) running 3.6 to
> 3.8, but we came across an interesting problem with carp...
>
> First we installed 3.8 from scratch on just fw2, and kept fw1 in
> production with 3.6.
> once fw2 was done, we tried just to plumb the carp interfaces with high
> advskew, so fw2 would still be BACKUP.
>
> So, we first added carp1 (described below) with this command:
> fw2# sh /etc/netstart carp1.
Hi,
the problem is, that if you run /etc/netstart on an already configured
interface you'll end w/ a different order of your IP addresses.
Carp calculates a configuration hash over of all addresses of an
interface. If the order is changed, the hash is different and
therefore the backup hosts ignore the carp packets and become master.
As a workaround you could destroy the carp interfaces first:
# ifconfig carp1 destroy && sh /etc/netstart carp1
In 3.9 we always compute the hash w/ the IP addresses in sorted order.
This will solve your problem.
But please note, that you might experience interop problems between
carp hosts running 3.9 and pre-3.9.
Marco
