NIC card problems....

Peter Jeremy PeterJeremy at
Sun Jan 23 12:05:20 PST 2005

On Sun, 2005-Jan-23 05:57:53 -0800, Net Virtual Mailing Lists wrote:
>  It would be nice if somewhere there was
>some statement of a "fact" that NIC ____ is known to work well with

I recall seeing quite a few such statements about different cards over
the years.  In general, such statements have a limited lifetime because
NIC vendors have an ongoing tendency to "improve" their NICs to the
point of incompatibility.  There are often useful comments about the
NICs at the top of the driver code for that NIC (though there's nothing
about your AN985).

>...  after several hours of *HEAVY* (I'm probably understating this)
>utilization I get:
>dc0: TX underrun -- increasing TX threshold
>dc0: TX underrun -- increasing TX threshold
>.. repeats numerous times..
>dc0: TX underrun -- using store and forward mode

Real DEC Tulip cards do this when running Tru64 as well.  My guess is that
it's a bug in the NIC.  (And it looks like AMDtek have copied it).

>.. at this point the system simply reboots.

This is undesirable.  However, you have not provided any information that
would allow anyone to assist you.  Please have a look at

>  I have attempted to apply a
>patch (<>) which I
>found which patches sys/pci/if_dcreg.h and sys/pci/if_dc.c.

This PR is closed which means that the patches (or functional equivalents)
should have already been applied.

>  I would just like
>someone somewhere to tell me what is a stable NIC to use for FreeBSD,

I've been using Intel EtherExpress Pro/100+ cards (fxp driver) in some
systems where the network gets hammered and haven't had any problems.

Peter Jeremy

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