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

From: Martin Knoblauch
Date: Tue Jan 06 2004 - 06:12:51 EST


>> 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 :-)?

so, I append two traces from "tcpdump -i eth1 multicast". "good" is
from the 2.4.20.-18.7smp kernel, "bad" is from 2.4.22.

What is interesting from a first look is the fact that the 2.4.22
kernel seems to drop/miss packets from outside that go to a
nonpriviledged port on the multicast group. Ganglia uses port 8649. In
the "bad" case, packets for "239.2.11.71.8649" only come from the local
box. Does this ring any bells for "tg3" or the networking code?

Cheers
Martin

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

Attachment: bad.tcpdump
Description: bad.tcpdump

Attachment: good.tcpdump
Description: good.tcpdump