Re: Any changes in Multicast code between 2.4.20 and 2.4.22/23 ?

[Martin Knoblauch]

--- David Stevens <dlstevens@xxxxxxxxxx> wrote:
> 
>
Hi David,
 
> 
> 
> Martin,
>       If you have other hosts on that network that have sent IGMP
> reports,
> then
> the reporter flag will be cleared-- only one member on a network
> needs to
> send
> reports. That doesn't prevent the host from receiving multicasts--
> presence
> in
> /proc/net/igmp indicates it did join the group.

OK. I just wondered, because all hosts running the 2.4.20-18.7smp
kernel (RH7.3 errata) show the "1" in the reporter field, while all
hosts running 2.4.22/2.4.23 (vanilla plus NFS fixes from Trond) show
"0".

>       Please send me some details about your set-up and I may be able
> to
> help.

 We are running 21 HP/DL380G3.Each has two internal Broadcom NICs. The
second one (eth1) is used for the Ganglia multicast.

 The kernels are 2.4.22 and 2.4.23 (now .24) with some NFS patches. In
the case of 2.4.24 those are:

01-posix_race
02-fix_commit
03-fix_osx
04-fix_lockd3
06-fix_unlink
07_seekdir

 from http://www.fys.uio.no/~trondmy/src/Linux-2.4.x/2.4.23-rc1 None of
those looks like it does something to multicasts. In the worst case I
could try to run with plain 2.4.22/23, but that would have to ait until
Wednesday.

 The kernel-config file is included.

>       First, are the sender and receiver on the same network, or are
> you
> using a multicast router?

 No. All systems are on the same network.

>       Second, can you send me a tcpdump-format packet trace
> (preferrably
> only the multicast traffic, and as small as you can make it)?

 What exactely do you want to see? On which box should I run tcpdump?
Which options (I'm not that deep into network debugging :-)?


>       You mentioned tg3-- have you tried this with other hardware
> that
> worked?
>

 The tg3 works with the 2.4.20-18.7smp (and earlier) kernels. It just
does not work with 2.4.22/23 (did not check 2.4.21). 

 Unfortunatelly I have no other boxes to test with. I only can say that
Ganglia never failed in this particular way on any setup.

Thanks
Martin

=====
------------------------------------------------------
Martin Knoblauch
email: k n o b i AT knobisoft DOT de
www:   http://www.knobisoft.de

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Description: config-2.4.24-1-msc