Very Computer

I have a 3Com Etherlink III card (3C509B-COMBO) which has just recently
started dropping selected packets. This only seems to happen with packets
which are 422 bytes or larger. For instance, flood pinging a nearby machine:

  cuiv ~# ping -f -s413 frank
  PING frank.trinity.unimelb.edu.au (203.28.240.1): 413 data bytes
  .
  --- frank.trinity.unimelb.edu.au ping statistics ---
  637 packets transmitted, 636 packets received, 0% packet loss
  round-trip min/avg/max = 1.9/2.8/6.2 ms

(No problems with 421 byte packets, but with 422...)

  cuiv ~# ping -f -s414 frank
  PING frank.trinity.unimelb.edu.au (203.28.240.1): 414 data bytes
  ..............................................................................................................
  --- frank.trinity.unimelb.edu.au ping statistics ---
  489 packets transmitted, 379 packets received, 22% packet loss
  round-trip min/avg/max = 2.1/2.7/5.2 ms

ifconfig gives:

  eth0      Link encap:10Mbps Ethernet  HWaddr 00:A0:24:06:E0:DA
            inet addr:203.28.241.191  Bcast:203.28.241.255  Mask:255.255.255.0
            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
            RX packets:7928 errors:235 dropped:235 overruns:0
            TX packets:6811 errors:0 dropped:0 overruns:0
            Interrupt:10 Base address:0x300

I'm using Donald Becker's driver, version 3c509.c:1.07 6/15/95, with
kernel 2.0.18 (RedHat 4.0) on a 100MHz 486.

The interesting thing is that this problem has started only recently, and
I haven't made any changes to the system, hardware or software. The DOS
diagnostic utilities which come with the card find no fault (for the Group
1 tests, the only ones I was able to run).

Any leads on what might be causing this (and how to fix it...) would be
much appreciated.

Thanks,

Tim.
--
Tim Bell                                      .--_|\

Department of Computer Science               \_.--._/
University of Melbourne, Australia                 v