Re: Any good method to check network overload?

[stefmit <stefmit () comcast net>]

Very good points. Here is one (minimal) tool that can address the packet size 
and/or minimal traffic checkup, for $0:

- get yourself a copy of Qcheck from:
http://www.netiq.com/qcheck/default.asp
then endpoints for whatever OS you're running from:
http://www.netiq.com/support/pe/pe.asp

Of course, in order to address the ping limitations, one can always use some 
open-source utilities such as hping2 and bping ...

Stef

On Wednesday 05 March 2003 11:01 pm, Mark Reardon wrote:
> I missed the original request but I saw the response about using ping and
> comparing results over time. I wanted to interject some points.
>
> Network overload needs a definition before you go too far. If you have
> batch type traffic and response time is not an issue, then overload is
> different than say SSH based user sessions. If you are transfering files
> and it gets done in time, then your fine.
>
> If your interactive sessions are the concern, then using a response
> measurement tool such as ping may be appropriate. However, ping tests tend
> to use the same size packet for each test. Networks may or may not function
> this way. Say for example a web site. Small packets in, large packets out
> is a common generalization. Therefore it is best to use something that
> emulates the typical traffic. A web response measurement tool is one way of
> doing it for web sites.
>
> All of the above also have the added feature of adding load while measuring
> it. That means you may be creating the very problem you want to avoid yet
> measure. This leads to methods that look at traffic measured at the server
> such as monitoring the TCP round trip timers (difficult to do and difficult
> to interpret) or looking at network devices and server statistics to check
> their load handling statistics.
>
> Sorry to be so verbose. The underlying point is that you need to be
> specific in defining what you want to measure and how you want to do it.
> Then look for proven tools. I have used Solarwinds and the stuff at the
> National Labs for Applied Network Research (dast.nlanr.net) also looks
> good. I'd also speak with your network equipment provider as sometimes they
> have tools for this as well (Cisco does).
>
> Good luck,
>
> Mark
>
>
> ----
> Mark Reardon
> Reardon Information Security Corporation
> 156 Blue Sky Drive
> Marietta, GA 30068
> (770) 565-0544
> (404) 444-0041 cell