Re: 2.0.13 Sockets Stuck on close

Hugues Talbot (Hugues.Talbot@dms.csiro.au)
Thu, 22 Aug 1996 09:21:46 +1000


Hello,

You replied to Christoph Lameter <clameter@miriam.fuller.edu>:

> >2. TCP sessions stall on busy machines.
>
> I have no outstanding reports of this problem that cannot be
> attributed to MTU mismatches on the endpoints of a point-to-point
> link. [...]

Sorry mate, but this is a real problem. I'm running 2.0.12,
pppd 2.2.0f, mtu=mru=296 over a 28.8k modem. In addition I have an
ethernet session running over a NE2000. All PPP interactive session
come to a standstill in under a minute. FTP/HTTP session do not. They
run fast and don't stall. Interactive sessions (telnet/rlogin) start
almost normally, then degrades real quick, then come to a complete
standstill.
If you start another session, the previous one restarts
magically for another minute, then things freeze again.

> Also, slow network connections to the outside world are not news
> unless you can exhibit a faster connection with different software
> in the same environment.

Well, this is very very simple: 2.0.8 DOES NOT HAVE THIS PROBLEM.
Same configuration, same everything. No problem. Rien. Nada.
All is well. Interactive session and everything is FAST. I've more
than once:

a) booted with 2.0.12
b) experienced the problem immediately
c) rebooted with 2.0.8
d) have no problem
e) rebooted with 2.0.12 again
f) experienced the problem again immediately.

In fact 2.0.8 is the kernel I'm running now and I'm quite
happy about it. I quite recommend it actually. Good one, this one.

I'm pretty sure that these ``lots of TCP one-liners''
introduced in 2.0.12 to ``improve the feeling of ppp'' according to
Linus are responsible for the problem.
I don't think that 2.0.1[34] cure the problem. Nothing
networky in the patches, apparently.
Sorry guys, but this is not a big fat success.

> tcpdump's of actual stalls are particularly useful.

I'll endeavour to do a tcpdump for you tonight. Tell me
if I can do something else to help. I'm willing.

__________Hugues Talbot, CSIRO Div Maths & Stats,______________
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