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Date:      Sat, 25 Jul 2009 15:04:24 +0200
From:      iprebeg@freebsd.org
To:        freebsd-net@freebsd.org
Subject:   Wrong multicast destination IP
Message-ID:  <20090725130424.GA24589@valeria.zesoi.fer.hr>

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In recent current kernel, it appears that IGMPv2 reports (not IGMPv3)
are sent to wrong multicast address. I'm trying to setup mcast routing
in this way:

.--.                     .--.                     .--.
|c1|-10.0.1.2---10.0.1.1-|mr|-10.0.2.1---10.0.2.2-|c2|
'--' em0             em0 '--' em2             em0 '--'

(em1 is used for SSH access)

mrouted is started on mr with configuration containing only one line:

>phyint em1 disable

and route is created:

>route add 224/24 -iface em0

Machine c1 issues command

>mcastread -v4 -s 10.0.2.2 em0 235.0.0.1 1337

and machine c2 has route

>route add 224/24 -iface em0

and issuse command

>mcastsend 235.0.0.1 1337

mr uses p4 kernel dating 24th of June and cX's use BETA2.

So, I have two problems. 

1) No packets are forwarded. I hope that reason is problem stated in 2).
   Anyway, I'd be happy if someone can confirm that I'm doing everything
   right. It would be also cool if someone could post XORP configuration
   that I can use for this configuration. I can see UDP packets reach em2 
   iface on mr.

2) Even all machines support IGMPv3, after I start mrouted, network
   converges to IGMPv2. What I see in tcpdump is that DIP of IGMPv2
   packets isn't in IGMP-CONTROL range (224.0.0.X), but it is set to IP
   of group that it tries to join ( 235.0.0.1 in this case ). This is
   not cast with IGMP leave or IGMPv3 reports which are generated by
   same commands after I kill mrouted and network again converges to
   IGMPv3.

TIA

iprebeg



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