Re: Multicast problem

[Stephen Hemminger <shemminger@linux-foundation.org>]

On Tue, 16 Oct 2007 22:07:35 +0200
"Joakim Tjernlund" <joakim.tjernlund@transmode.se> wrote:

> > -----Original Message-----
> > From: David Stevens [mailto:dlstevens@us.ibm.com] 
> > Sent: den 16 oktober 2007 21:46
> > To: Joakim Tjernlund
> > Cc: 'Netdev'; netdev-owner@vger.kernel.org
> > Subject: RE: Multicast problem
> > 
> > > dev_mcast and igmp looks:
> > > root@Challenger:/proc/net# m dev_mcast
> > > 1    eth0            1     0     01005e000001
> > > 2    eth1            1     0     01005e000001
> > 
> >         These are the hardware multicast addresses for
> > 224.0.0.1 (so, correct).
> > 
> > > root@Challenger:/proc/net# m igmp
> > > Idx     Device    : Count Querier       Group    Users 
> > Timer    Reporter
> > > 1       eth0      :     1      V3
> > >                                 E0000001     1 0:00000000 0
> > > 2       eth1      :     1      V2
> > >                                 E0000001     1 0:00000000 0
> > > 4       lo        :     0      V3
> > >                                 E0000001     1 0:00000000 0
> > 
> >         ...and these are the group memberships for 224.0.0.1, so
> > also correct. This should receive and answer pings to 224.0.0.1
> > as long as you don't have ICMP set to ignore broadcasts. You should
> > not need to put the device in promiscuous mode for a ping of
> > 224.0.0.1 to work, so if you do, then you have a driver, device
> > or switch problem.
> >         None of these interfaces have memberships in the OSPF groups,
> > so if you had OSPF running when you did this, it didn't join.
> > 
> >                                                         +-DLS
> > 
> 
> OK, so from all this and earlier mail I think that the device driver don't
> receive multicast pkgs. Tomorrow I will try the real OSPF test case with
> promisc mode enabled, se if that works. If so, it means there is
> a bug in the drivers(ucc_geth.c) set_multicast_list() function.
> 
> Thank you for helping me to narrow it down.
> 
>  Jocke

You can test multicast easily standalone with iperf:
http://dast.nlanr.net/Projects/Iperf/#multicast

-- 
Stephen Hemminger <shemminger@linux-foundation.org>