Re: tcp window size of 1

The Natural Philosopher wrote:

thorko wrote:
Hi guys,
I have a strange behavior on a Centos 5 machine. Whenever I connect
from
the internet to that machine using ssh I get a tcp window size of 1.
But
when I connect from the local network it is fine (it's around 30).
The machine is behind a firewall using NAT to forward any traffic from
www
to the same network card on which the local network resides.
Any kernel parameter is the default which comes with Centos 5.

net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_wmem = 4096 65536 16777216
net.ipv4.tcp_mem = 786432 1048576 1572864
net.core.rmem_default = 110592
net.core.wmem_default = 110592
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_sack = 1
net.ipv4.tcp_window_scaling = 1

Do you have any clue why this happens?
Thanks for your attention.
Ciao
Thorsten

a few clues..windows sizes are, I believe, negotiated between segments,
and somehow the lowest is used to control the connection.

There have been issues with latest Linux kernels, in that they are
configured to negotiate very large windows sizes that many older routers
are unable to handle correctly, and Weird *** Happens.

A google on linux tcp windows sizes will give you chapter and verse on
that particular issue, and the fixes (basically revert to older style
window negotiations) This MAY fix the problem. Or may not. Either way
I'd be personally interested to hear about it.

Maybe we should just ask Jerry ;)

--
Dancin in the ruins tonight
Tayo'y Mga Pinoy
.

Quantcast