On Wed, Jun 27, 2007 at 02:37:25PM -0400, Daniel Ouellet wrote: > Reyk Floeter wrote: > >you have to enable ip multicast on the systems. > > Shouldn't it be included in the man page then? May be I miss it, but I > read them many times over to try to figure it out. I sure will test > tonight when the servers are a bit less use. > > >by default, openbsd rejects any ip multicast traffic by adding a route > >route -qn add -net 224.0.0.0/4 -interface 127.0.0.1 -reject > > One question however. CARP also use multicast and didn't need this, only > net.inet.carp.preempt=1 in that specific case. I guess I am not > understanding something here, or just not clear to me. Should it be > rejected in CARP case as well then? I know both are not related, but I > am more referring at the logic of how each work and both use multicast > and in one case, the man page said to enable net.inet.carp.preempt=1 > and nothing about adding multicast as well. Or is that does the same > thing here? >
The reject route only triggers for UDP traffic. So carp (which runs inside the kernel) and ospfd (uses a raw socket) are not affected. On the other hand ripd/routed and other tools using multicast over UDP hit that route and when sending all packets are discrded. > >try to set > >multicast_host=dc0 > >in /etc/rc.conf or /etc/rc.conf.local > > I sure will try. In any case, I sure can use unicast only as well. But I > will try to know for sure. > I prefer to add a specific host route to 127.0.0.1 to let specific multicast traffic through the box. ripd -- as it already plays around with the routing table -- add such a route on startup but I think that's overkill for spamd. -- :wq Claudio