Not to whine, but [more details on NIC problem]

[James McKenzie]

Richard Crawford wrote:
> On Mon, 2004-12-20 at 17:16, James Wilkinson wrote:
> 
> 

> Bill:  I, too, have never encountered a problem like this in the dozen
> or so RH, Debian, or SuSE installations I've done.  The same problem did
> show up when I installed the SMP version of the 2.6 kernel with a SuSE
> 9.2 installation, which makes me think that the problem might be with
> the 2.6 kernel and not with Fedora Core.
> 
> William and Jim: It is indeed a 3com card.  More specifically,
> 3c905C-TX/TX-M [Tornado] (rev 74).  The bug file that William pointed to
> looks familiar, but I have never encountered this problem before under
> any other kernel; I even had the SMP version of a 2.4 kernel running
> before without difficulties.
> 
> The computer can see the network through the card, and I can ping other
> computers in my network and on the Internet, but there is significant
> packet loss -- between 36% and 94%.

Try this:

Ping the interface itself.  This may sound strange, but it points out 
whether or not the driver or the NIC is causing the problem.  Errors 
here point to a malfunctioning driver or NIC.  Since you state this 
problem only occurs with SMP kernels, you may have to do a little to a 
lot of work to overcome this problem.  However, I suspect that you have 
to remake the appropriate module to work with SMP kernels vice single 
processor kernels.
Next ping the default gateway, not another system on the network. 
Depending on whether the default gateway is connected through a direct 
connection, a hub or a switch, you may get a collision rate, but NEVER 
should you get a bad packet error (runts or longs) without a 
corresponding collision error.  If you get errors here, with no errors 
when you ping the NIC IP address, you may have a noisy cable, a 
misconfigured or defunct hub/switch/router or a bad NIC jack or 
defective  transmitter/receiver on the NIC.
Lastly, ping the local (localhost or 127.0.0.1) system interface.  You 
should NEVER get a dropped packet or an error pinging the local 
interface.  If you do, this points out a badly configured TCP/IP stack.

Troubleshooting with a different NIC, preferably from a different 
manufacturer, can induce other problems.  However, if a different NIC 
works when your 3COM card does not, can be the 'solution'.

In any case, you do have some testing and possible work to do. 
Hopefully, the problem is within the physical network and not with your 
Linux system.

James McKenzie