It seems my NetBSD-3.99.3/i386 box isn't routing multicast across vlans..
What have I missed?

options         MROUTING        # IP multicast routing
#options        PIM             # Protocol Independent Multicast

I take it PIM is not necessary?


ex0: flags=8a63<UP,BROADCAST,NOTRAILERS,RUNNING,ALLMULTI,SIMPLEX,MULTICAST> mtu 
1500
        capabilities=3f00<IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx,TCP4CSUM_Tx,UDP4CSUM
_Rx,UDP4CSUM_Tx>
        enabled=3f00<IP4CSUM_Rx,IP4CSUM_Tx,TCP4CSUM_Rx,TCP4CSUM_Tx,UDP4CSUM_Rx,U
DP4CSUM_Tx>
        address: 00:0a:5e:52:f6:69
        media: Ethernet autoselect (100baseTX full-duplex)
        status: active
vlan1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        vlan: 1210 parent: ex0
        address: 00:0a:5e:52:f6:69
        inet 192.168.80.62 netmask 0xfffff000 broadcast 192.168.95.255
vlan3: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        vlan: 1485 parent: ex0
        address: 00:0a:5e:52:f6:69
        inet 192.168.204.62 netmask 0xfffff000 broadcast 192.168.207.255


So, ALLMULTI is defined on ex0, and the vlans seem happy with multicast.

mrouted is running with the default all commented out mrouted.conf file.
I thought this meant it would forward multicast packets to all interfaces
with MULTICAST, and indeed mrinfo says

127.0.0.1 (localhost) [version 3.8,prune,genid,mtrace]:
  192.168.80.62 -> 0.0.0.0 (local) [1/1/querier/leaf]
  192.168.204.62 -> 0.0.0.0 (local) [1/1/querier/leaf]


The aim is to multicast ghost images. The server is at 192.168.80.12, and
a client at 192.168.204.227. I see the igmp requests come in on the
interfaces, and indeed mrouted.cache contains:

Multicast Routing Cache Table (2 entries)
 Origin             Mcast-group     CTmr  Age Ptmr IVif Forwvifs
 192.168.192/20     224.77.0.0        2m   4m    -  3   
>192.168.204.227
 192.168.80/20      224.77.1.0        2m   4m    -  1   
>192.168.80.12

However, no packets seem to be copied from one vlan to the other, which I
think is why they each created a different group.

There are a few other vlans and the entire routing table is:

Multicast Routing Table (6 entries)
 Origin-Subnet      From-Gateway    Metric Tmr In-Vif  Out-Vifs
 192.168.240/20                        1   150   0    1* 2* 3* 4* 5*
 192.168.192/20                        1   150   3    0* 1* 2* 4* 5*
 192.168.80/20                         1   150   1    0* 2* 3* 4* 5*
 192.168.32/20                         1   150   5    0* 1* 2* 3* 4*
 192.168.16/20                         1   150   4    0* 1* 2* 3* 5*
 192.168.0/20                          1   150   2    0* 1* 3* 4* 5*

and the ipf rules are

block in log quick all with short
block in log quick all with ipopts
pass in quick proto icmp all
pass out quick proto icmp all
pass out quick on vlan1 all
pass in quick on vlan1 all
pass out quick on vlan3 all
pass in quick on vlan3 all
pass in  quick on lo0 all
pass out quick on lo0 all

so not exactly "restrictive".


Cheers,

Patrick