BGP password behaviour

[Ondrej Zajicek]

On Sun, Apr 28, 2013 at 05:48:32PM +0200, Dan Rimal wrote:
> Hello,
>
> today i have had very strange experience with bird. Few days ago (approx  
> 6 days) i have established bgp session with bgp password attribute.  
> Since established this session, i have got messages in system log like 
> this:
>
> kernel: [2956936.985539] MD5 Hash failed for (195.81.xxx.yy,  
> 179)->(195.81.xxx.yy, 46595)
> kernel: [2956936.985761] huh, entered softirq 3 NET_RX ffffffff814e7060  
> preempt_count 00000100, exited with 00000101?
...
> I don't know exactly if this bug is kernel related or bird related, i  
> don't know if BUG message is related to his precedesor "MD5 hash failed"  
> message. I read a little bit about "BUG: scheduling while atomic"..  
> always was related to kernel code, not userspace.. it is a bit  
> confusing. After that, i have disabled md5 auth from affected BGP  
> session and messages are completely gone.

Hello

Well, MD5 authenticated TCP used in BGP is almost completely handled
by kernel (BIRD just enables that for given IP pair and sets password),
so any directly related problem is almost surely a kernel issue.

The crash could be unrelated (i would guess), but unless you have a core
dump, it is hard to say. We have some reports of rare crashes during
reconfiguration, but they were related to real reconfiguration (e.g.
protocol removing/adding), not just reloading for the purpose of
logrotate. Is there anything interesting in BIRD log, if so, could
you send it to me?

-- 
Elen sila lumenn' omentielvo

Ondrej 'SanTiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."
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