Subject: Re: multicast vlans
To: None <tech-net@netbsd.org>
From: Patrick Welche <prlw1@newn.cam.ac.uk>
List: tech-net
Date: 06/01/2005 14:42:19
I missed part of the story!
On Tue, May 31, 2005 at 05:43:45PM +0100, Patrick Welche wrote:
> 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.
mrouted.dump doesn't mention the Mcast-groups listed in the table above:
vifs_with_neighbors = 0
Virtual Interface Table
Vif Name Local-Address M Thr Rate Flags
1 vlan1 192.168.80.62 subnet: 192.168.80/20 1 1 0 querier leaf
pkts in : 5
pkts out: 0
3 vlan3 192.168.204.62 subnet: 192.168.192/20 1 1 0 querier leaf
groups: 239.255.255.253
224.0.1.60
pkts in : 10
pkts out: 0
> 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