2.1.98 link freezes --> 2.1.99 machine locks up

Adam J. Richter (adam@yggdrasil.com)
Sun, 3 May 1998 16:05:39 -0700

Bug report (FYI)

Network toplogy:

ethernet 28.8kbps modem line
2.1.99 2.1.98 2.0.0

When my desk workstation (adam.yggdrasil.com) was runing
Linux 2.1.~75-2.1.98 a direct telnet session from my home notebook
computer (adamhome) to my desk workstation would sometimes freeze
for about ten minutes and then finally close with an error like
"connection reset by peer." During this time, I could make other
directly telnet connections, but those connections seemed to freeze
much more easily if one connection was already frozen. The freezes
always occurred when at least one screenful of data was in the process
of being sent from my desk workstation to my home notebook computer.
Note that rlogin connections would freeze as often as telnet connection,
but I never had an any other type of connection freeze, such as FTP,
although I use such connections very rarely.

Somebody had suggested to me that the problem was probably
in the fact that my home computer was running 2.0.0, and that I
should upgrade that first, which is completely reasonable. (I am
fighting what appears to be a bug in the regular msdos filesystem
under 2.1.99 to do that upgrade right now, but that's another matter.)
Anyhow, when I upgrade my desk workstation, the behavior changed.
Instead of just the one telnet connection freezing, my 2.1.99 desktop
workstation locks up hard. There is no final kernel message and the
keyboard is completely nonresponsive. So, this definitely is
a problem with the 2.1.99 networking.

This problem never occurs when if I telnet to the machine
in the middle and then to my desktop workstation, and it only
occurs when a lot of output is about to be sent to my home
machine. Therefore, I believe that the problem is probably
triggered by a packet being dropped.

Anyhow, I hope this information is useful to those tinkering
with the networking code (I think this is primarily Dave Miller right
now) and anyone trying to isolate a similar problem.

Adam J. Richter __ ______________ 4880 Stevens Creek Blvd, Suite 205
adam@yggdrasil.com \ / San Jose, California 95129-1034
+1 408 261-6630 | g g d r a s i l United States of America
fax +1 408 261-6631 "Free Software For The Rest Of Us."

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