On Tue, Aug 04, 2009 at 03:15:25PM +0200, Federico wrote:
> Rosen Iliev wrote:
> > Hi Federico,
> >
> > Did you try to change the balancing mode to ip-unicast or ip-stealth?
> >
> > from man carp(4)
>
> I just tried with ip-unicast, but both machines stop working.
> Do I have to think it's a switch related problem?
ip-unicast needs special care:
citing carp(4):
"For scenarios where a hub is used it is not necessary to use
a multicast MAC and it is safe to use
the ip-unicast mode. Managable switches can usually be tricked into
forwarding unicast traffic to all cluster nodes ports by configuring
them into some sort of monitoring mode."
As a basic test to see if your switch is playing along, you should
run tcpdump on both machines and verify that the traffic towards
the cluster is received on both sides. It is essential.
The switch needs to send the traffic to all nodes in the cluster,
if it does not do that, IP balancing cannot work.
Marco
