2010/1/26 Michele Marchetto <myde...@openbeer.it>: > Il giorno mar, 26/01/2010 alle 00.05 -0200, Christiano F. Haesbaert ha > scritto: >> Hi there, sorry for another annoying question, >> >> It seems ripd will explicitly add a route to rip's multicast address. > > Every single IGP routing daemon does this. The reason is simple: > > $ route -n show > Routing tables > > Internet: > Destination Gateway Flags Refs Use Mtu Prio Iface > [snip] > 224/4 127.0.0.1 URS 0 0 33200 8 lo0 > > >
Please correct me, If understood correctly, without the route to lo0, the IP_MULTICAST_IF would have no effect as the packet would be sent to the interface which has a route for the ip-dst (like default route). And by having the route to lo0, I force the kernel to look at IP_MULTICAST_IF and possibly forward the packet to another interface. I'm confused about the interaction between routes and the IP_MULTICAST_IF as I thought the route wasn't necessary. Thanks
