Subject: Re: momentary freezes in -current
To: None <netbsd-users@netbsd.org>
From: Mark Cullen <mark.r.cullen@gmail.com>
List: netbsd-users
Date: 08/06/2006 12:09:04
Martijn van Buul wrote:
> It occurred to me that Perry E. Metzger wrote in gmane.os.netbsd.ports.i386:
>> Jukka Marin <jmarin@embedtronics.fi> writes:
>>> An update:
>> [...]
>>> The system does _not_ freeze, but the network interface does.
>> This sounds like A PR I've filed, #34023.
>>
>> http://www.netbsd.org/cgi-bin/query-pr-single.pl?number=34023
> 
> Hmm. On my system I do get those stalls as well, but they're infrequent (Once
> every 2 or 3 weeks, maybe), I do _not_ get the watchdog message, and I've
> found several peculiarities: 
> 
> * Restarting dhclient fixes the problem - at least temporarily.
> 
> * the network card isn't *really* dead. When I run tcpdump on it, I still see 
>   packets arrive with my IP as destination - it just seems like the NIC 
>   doesn't realise it is the intended target. I don't see any packets
>   *leaving* the interface using the assigned IP. It makes me wonder if 
>   packets don't get dropped somewhere, and it makes me wonder if it's really
>   the nfe0 driver at fault.
> 
> * In fact, the NIC still works happily on an second IP. My modem uses a 
>   private IP for configuration purposes (172.19.3.1), and this seems to work
>   just fine if I assign an appropriate alias (ifconfig nfe0 alias 172.19.3.2)
>   while the primary (public) IP remains dead. 
> 
> I have yet to figure out exactly what dhclient's doing that makes any 
> difference. Taking the interface down- and up doesn't help, re-applying the
> IP address doesn't help, putting it into promiscous mode doesn't help, so
> I'm slowly starting to wonder what kind of magic dhclient is doing :)

Possibly a silly suggestion, but dhclient would send some broadcast 
packets, wouldn't it? Perhaps try sending some broadcast packets, 
somehow, next time it happens and see if that makes it come back alive 
again?

> 
> Next time it's doing this, I intend to eavesdrop using a third NIC; I hope
> I won't be changing the situation too much, though; I'd have to run things
> through a hub, and the only _hub_ I have is 10 mbit.
> 
> All of this is on an Athlon64, Asus A8N-E (nForce 4, nfe0) running 
> current. (using the amd64 port, however).
> 
> 


-- 
Mark Cullen <mark.r.cullen@gmail.com>
BSc (Hons), Computer Science