IBM IMM shared port

[Dima Veselov <kab00m%lich.phys.spbu.ru@localhost>]

Greetings!

I have an IBM x3200 M3 server with built-in IMM IPMI service
processor. This server have IPMI network port shared with first network 
card. This setup is quite popular and I have several different servers 
having no issues with that. While booting, OS initialize network 
interface and IPMI stop responding for a while, then connection is 
restored. My guess is that happens because of internal switch reset when 
network interface get reset.

But on this particular machine internal switch goes down upon wm0 
initialization and will not function until interface will come up fully 
configured. I have kernel console running on tty01 and that means I may 
not use it if server goes in single-user at all.

What experiment can be conducted to analyze what part of code provoke 
network disruption? Can I make same thing happen on live system?
In live system I can ping IPMI and bring interface up or down and both 
make not more than 2 packets lost.

--
Dima Veselov
Physics R&D Establishment of Saint-Petersburg University