When I use netbsd as a multicast router, running the latest mrouted
v3.5, I occasionally get kernel panics. I have very limited access to
the console, and therefore i disabled the in-kernel debugger in order
to let the machine reboot. Therefore I have no information about whats
causing these panics, but it seems to happen when mrouted is running.
And, when starting up, I get this error message (mrouted -d 2) among
the init-info:

Virtual Interface Table
Vif  Name  Local-Address                               M  Thr  Rate   Flags
 0    ep0  129.240.21.64   subnet: 129.240.20/23       1   1      0   querier
12:40:12.051 warning - SIOCGETVIFCNT fails

 1    ep0  129.240.21.64   tunnel: 193.71.2.80         3   1    500  
12:40:12.057 warning - SIOCGETVIFCNT fails

I also get lots of

12:48:14.109 warning - age_table_entry: SIOCGETSGCNT failing for (129.215.200.197 224.0.1.13): Device not configured
12:48:14.138 warning - age_table_entry: SIOCGETSGCNT failing for (129.13.10.121 224.0.1.14): Device not configured
12:48:14.164 warning - age_table_entry: SIOCGETSGCNT failing for (194.104.0.50 224.2.17.10): Device not configured

Seems like the socket io-calls have some trouble with multicast.

-aage