If this router is not doing some kind of proxying, tuning tcp related
kernel bits will not impact "long fat pipe" or "long fat network" issues.
The place that needs to be tuned for larger window sizes/scaling is the
web server.
http://www.psc.edu/networking/projects/tcptune/#Linux
or search for "Linux TCP tuning" or "large fat pipes"
Also make sure your firewall isn't "helping" you out by "cleaning up"
the TCP SYN/ACK sequence and fiddling with the window scaling stuff.
Also if you have load balancers, they might break this stuff as well.
Good luck,
-Allen
Chris wrote:
Thanks for all the answers. I'm currently going down the path of looking at
IPtables' conntrack slowing the forwarding rate.
If I can't find any more docs then I'll boot the router with a kernel
without any IPtables built-in and see if that's it.
As Lee said "rollback" ! That's the last change to the box. If I can rule
out the logging of traffic from conntrack is slowing down
the forwarding then I can look into hardware further ;-)
Chris
