Tool for testing network...

[mowtnman]

I am experiencing some bottlenecks in the networks. Atleast that is the way it is percieved. I am trying to prove that it is not the network and the problem relies elsewhere. I am looking for a good tool that will test the connection times to other resources in our LAN- i.e. a host acessing a file on the file server may take up to a minute with user 1 while user 2 was able to pull up the file in 10 sec.,etc.

Does anyone know of a good tool for testing / troubleshooting this kind of scenario?.... because if my network is bottlenecking I want to be able to validate that.

Thanks for your input.

[donewald]

There are a lot of things you'd need to measure to get a good idea of application latency... Here are some things you can do to remove the network from your problem equation.

1. Measure BW to ensure you have no congestion points: MRTG is a freeware tool that can graphically show you utilization of all your SNMP managed devices (interface in/out). This can be modified to measure almost anything you can poll from and SNMP agent.

Here's the URL for MRTG:

http://people.ee.ethz.ch/~oetiker/webtools/mrtg/

2. Mesure Network Latency between your devices to ensure no one thing is holding onto packets for to long before forwarding. Cisco has a Cisco Service Assurance (SA) Agent that will do this. Look it up on CCO and see if it will meet your needs.

3. Application latency takes agents installed in your application servers which Concord network Health can do..

4. Network Activity / Failure Analysis. When you have a lot of network devices you might want to know when links go up and down or if a bad event happens on the network with one of your devices. Best Practices of network management shows that you should setup logging to syslog/trapd.log facility to help manage and trend these events as well.

Hope this helps you,

Don

[scottmac]

QCheck from NetIQ (www.netiq.com) has a point-to-point tool that'll measure throughput, latency, and packet drop. This is a "little brother" (and free) version of Chariot - an Industry recognized testing and evaluation tool.

Qcheck is an application-level testing tool, so it measures the entire connection (allows for machine comparison as well as network performacnce).

Good Luck

Scott

[mowtnman]

thanks for the info. I will download the program and give it a try.

Marcus

[9akniveton]

Check out ttcp, it's an undocumented Cisco command and there are also exe files for unix, linux, windows, etc ...

[hbaerten]

The command 'ttcp' does not work on my testrouter (2611 with 12.2(10b))...

Looking for a linux version I found http://www.linuxtested.com/linux_tools.html which lists ttcp (including a newer nttcp) as well as various other test programs. Haven't used any of these myself yet, so I cannot comment on any of them.

hth

Herbert

[mowtnman]

TTCP did not work on my router as well. It is definately a command on certain IOS's only.

I found that Qcheck was a great tool (simple to use) and it provided me the data I needed to pinpoint the problem.

For all of you out there interested: It wasn't a network problem (I'll assume most of you knew that already) ...

Thanks for the help guys.

[bradley_kneller]

If you have it, Network Associates Sniffer is a great tool for a problem like this.

Sniffer will make a number of diagnosises on it's own, that may point to underlying problems. But best of all, you could compare packet by packet from one client to the next.

Don't forget causes of poor performance could be any of:

- The server (is disk I/O, memory, or processing impacted? Are the adapters set up right?)

- The client PC (Is the client doing a lot in the background already? Is the PC set up the correct distance from the closest repeater? Is one PC on a busy shared environment compared to the other?)

- Protocols (Does one PC have more protocols enabled then you expect (NETBEUI, IPX, APPLETALK, TCP/IP... we restrict user ability to turn these on.)

- Network (Is the problem more likely to be related to latency or bandwidth?)

I like to keep a copy of in-house applications as a benchmark sniff when they are deployed (and the user is happy). What is "slow" response? You need to have something to compare to, and then changes from sniff to sniff may give you an idea of where to look.

[gpelchen]

Yeah the systems and desktop guys allways say its the network!

Try this free Lucent tool (VitalAgent) which is great to find bottlenecks.

Logs application performance over time and identifies bottlenecks in the PC, network , server and application.

See http://www.lucent.com/press/0201/010212.nsb.html

XLucent TAC engineer, now back in the Cisco world ;-)

[brad-denham]

The download from Lucent (US) is not available anymore, (al least when I tried I couldn't connect to the site). But I did find Vital Agent at:

http://www.lucent.sk/vitalagent.php.