Re: 2.6.17 regression: Very slow net transfer from some hosts

From: John Heffner
Date: Tue Apr 11 2006 - 20:35:07 EST


Daniel Drake wrote:
Stephen Hemminger wrote:
Turn off TCP window scaling, your performance will be limited but about
as good as you can get with a corrupting firewall in between.

[snip]

For anyone else interested, the ISP is NTL (UK). The fix:

echo "4096 16384 131072 " > /proc/sys/net/ipv4/tcp_wmem
echo "4096 87380 174760 " > /proc/sys/net/ipv4/tcp_rmem

For the record, I think Stephen's suggested workaround is better:

echo 0 > /proc/sys/net/ipv4/tcp_window_scaling

It will prevent the other end of the connection from using a window scale, so it "fixes" both directions of the connection, not just receiving.

Thanks,
-John
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