Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!asuvax!ncar!ico!dougm
From: dougm@ico.isc.com (Doug McCallum)
Newsgroups: comp.unix.sysv386
Subject: Re: ISC TCP/IP 1.2 hangs?
Message-ID: <1991Jun11.152602.22404@ico.isc.com>
Date: 11 Jun 91 15:26:02 GMT
References: <1991Jun06.224153.209@pinhead.pegasus.com> <4104@merk.UUCP>
Reply-To: dougm@ico.ISC.COM (Doug McCallum)
Organization: Interactive Systems Corp., Boulder CO
Lines: 44

In article <4104@merk.UUCP> brennan@merk.UUCP (Rich Brennan) writes:
...
>It looks like a few people are taking the pipe on this one. I've got the
>same (and other) problems. Wild guess: WD8003 or the WD8003 driver have
>problems with "high speed" machines, e.g. race conditions in the driver.

There are a number of known problems with TCP/IP 1.2 that are being worked
on for the TCP/IP 1.3 release later this summer.  These include a number of
conditions that cause TCP to get hung connections.  They aren't related to
the WD driver (there could be other problems there but we haven't seen them).

>
>.3. My problem is that I've noticed that TCP/IP 1.2 is hanging on me
>.   about once a week now. Sessions will abruptly hang. The processes
>.   and session are still showing as active as reported by 'ps' and
>.   'netstat'. However, there is no way to ping the ISC UNIX box from a
>.   remote station. The ISC UNIX box itself appears to be running ok, except
>.   for that fact that all network capabilities are lost (it can't ping a
>.   remote station either).
>
>I'm able to induce this easily, too. See if TCP/IP is really hung: ping
>"localhost". When my machine hangs, localhost still responds to pings,
>meaning the trouble is not in TCP/IP, but in the ethernet controller/driver
>subsystem.

One of the bugs is aggravated by using the ping command.  You can easily 
get random hung connections by letting ping just run free.  Packets get lost
(actually they don't ever get sent out on the net) and sometimes it interferes
with TCP.

>
>Another posting here (a reply to my earlier whining) said ISC is working on
>these bugs. In the meantime, I'm going to try to snag a 3c503 card to see
>if that driver is more robust.

I suspect that the WD driver is more robust than the 3C503 driver although both
should be fine.  There may be some systems that have problems with older WD
cards so hardware can't be ruled out but in those cases the problems will
usually appear as the network not working at all and will be hardware related
not software.

Doug McCallum
Interactive Systems Corp
dougm@ico.isc.com