Hello
I experienced strange problem with bandwith.
My CentOS 4.3 x86_64 server is a gateway to Internet.
The uplink is 20 Mbps full duplex
Eth card is part of NForce4 chipset, the module is "forcedeth"
As a testing tool we use "iperf" http://dast.nlanr.net/Projects/Iperf/
By test we decide downloda is only 10 Mbps (upload is 18-20 Mbps)
The first suspect was ISP, so we did test in cooperation.
ISP Our site
FreeBSD ========= FreeBSD (ISP test machine)
TCP&UDP down 20 Mbps TCP&UDP up 20 Mbps
TCP&UDP up 20 Mbps TCP&UDP down 20 Mbps
result: link is Ok
The second and final suspect was our gateway:
ISP Our site
FreeBSD ========= CentOS 4.3
UDP down 20 Mbps UDP up 20 Mbps
UDP up 20 Mbps UDP down 20 Mbps
BUT
TCP down 20 Mbps TCP up 20 Mbps
TCP up 10-12 Mbps TCP down 10-12 Mbps
SO: there is an problem with TCP ???
At the time of testing there was NO iptable rules or shaping enabled ...
Where to find? I realy do not know.
Petr Kl?ma
e-mail: qaxi@xxxxxxxxx
