Help needed: TCP Wizards (was 8.0-RC1 NFS client timeout issue)

Rick Macklem rmacklem at
Fri Nov 6 20:23:12 UTC 2009

On Thu, 5 Nov 2009, Rui Paulo wrote:

> Are you running TSO?
Wow, I owe you a beer:-) That was the magic bullet...

I'm a dinosaur, so when I first saw this, I thought of that wonderful
time sharing front end to IBM mainframes I had the priviledge of using
in the 70s. (There was also a TSO emulator in the early Unix releases,
which set your terminal to the worst possible setting imaginable and
introduced delays of seconds when you tried to do anything. It was
pretty funny for those of us who had experienced the real thing.)

Anyhow, I figured you probably didn't mean this so I grep'd around
and found net.inet.tcp.tso, set it to 0 and...the problem went away.
(I have gotten a RST for the new port# once since then, but it was
in the middle of the 3way handshake instead of after it, so it didn't
cause any grief, just another 3way handshake right away.)

I have no idea if the problem is something generic w.r.t. TSO or specific
to the Intel 82801BA/CAM and/or the fxp driver for it. (I checked and none 
of the other net cards I have lying around have TSO support, so I can't 
test this by replacing the net card/driver.)

Does anyone know enough about TSO to know if the problem is net chip
specific of generic to using it?

Thanks for the help. I don't think I would have ever found that, rick

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