[CentOS] Multicast packages dropped

Tue Feb 25 11:46:13 UTC 2014
Brian Miller <centos at fullnote.com>

On Tue, 2014-02-25 at 11:12 +0000, Uwe.Poliak at amann.com wrote:
> Hi,
> 
> I have recently updated one of my systems from CentOs 6.4 to CentOS 6.5.
> This systems is used as a RIPv2 routing server with quagga which is the termination point of some GRE tunnels.
> 
> While running CentOS 6.4 I see the multicast packages arriving at the eth0 and the GRE tunnel interface.
> While running under CentOs 6.5 I can see the multicast packages arriving at the eth0 but not on the GRE tunnel interface.
> I am receiving and sending routes at the eth0 interface, but I am only able to send updates through the GRE tunnel not receive them.
> All interfaces are multicast enabled:
 [snip]

Between the -358 and -431 kernel releases from upstream there has been a
lot of multicast weirdness going on.  If you're currently running -431
try rolling back to the last -358 (or vice-versa) and rerun your tests
to see if the behavior changes.