[CentOS] Performance of CentOS as a NAT gateway

Bart Schaefer barton.schaefer at gmail.com
Mon Sep 10 19:50:42 UTC 2007

On 9/9/07, Barry Brimer <lists at brimer.org> wrote:
> Maybe it is time for some kernel networking tuning.

After doing a bit of research:


I ended up with this:

net.core.rmem_default = 873800
net.core.wmem_default = 655360
net.core.rmem_max = 8738000
net.core.wmem_max = 6553600
net.ipv4.tcp_rmem = 8192 873800 8738000
net.ipv4.tcp_wmem = 4096 655360 6553600
net.ipv4.tcp_mem = 195584 873800 8738000

(The first number in tcp_mem is the original default.)


ifconfig eth0 txqueuelen 1000
ifconfig eth1 txqueuelen 1000

Unfortunately so far this doesn't seem to have made any difference.
We've had a load peak going since early this morning and the traffic
looks exactly like it did last week.

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