It is unlikely the difference is due to lost packets,
particularly as you do not complain of the performance.
It is likely that the difference is due to the server
and MRTG measuring throughput at different layers. The
server is likely measuring application layer performance,
and MRTG is likely including protocol and link layer
overhead (using a simple metric such as SNMP octets-out)
that the server does not count.
If you want to generate traffic, protocol analyzers can
usually do this and have fine granularity (protocols,
If you want to verify you are not really seeing packet
loss, and want a benchmark throughput program for your
server, look at IPerf.
Subject: Simulating bandwidth tools?
Date: Tue, 08 Jul 2003 22:35:14 GMT
I have been searching Google for a while, and I think I'm just not
searching for the right thing.
I am having some problems with our network, but not all the time. I am
seeing some packet loss when there is a lot of network traffic
(sustained 5-7Mb/s), but not so much when it's lower. The problem seems
very transient, so I am look for tools to help me figure out what's wrong.
The main thing I was hoping to find is a bandwidth simulator, something
I can say "push X Mb/s", with the goal of gettings a reliable packet
What brought this up is we have MRTG running, and when the server is
pushing 6Mb/s, MRTG is reporting ~8Mb/s. We think it's due to packet
loss, but it is very hard to pin down.
Any suggestions would be appreciated.