how to monitor bandwidth usage?

[cfrut]

I'm looking for some help interpretting the show interface
commands.
I have a 4 site Frame Relay setup with one PVC at the host site going to the internet. The bandwidth on the internet should be at 128K.
I basically want to see, possibly in real time, the bandwidth to the internet that is being used when I start/stop a certain FTP program.

I've looked at the show int serial0:1.31 and got a txload and rxload both are usually around 10/255.
Are these numbers an effective way of measuring the percentage of bandwidth used? 0/255 = zero and 255/255 = bandwith maxed out

Also I've got the 30 second input/output rates from the show interface serial0:1
These show a bit rate but I believe it is counting all the subinterfaces I have. IE: ser0:1.15 , ser0:1.17 , ser0:1.31 , etc. I can't seem to find a bit rate for a single sub interface (ser0:1.31)

Any help on interpretting the output of these comands is appreciated. Or if there are any other commands that might help me make a quick and easy bandwidth usage estimate?

 

[routerman]

When your looking at sub interfaces these counters reflect the value on your physical, as you have found out, certainly thats the case on frame links.

With FTP when you transfer a file you usually get a throughput rate, would that be good enough?

If not, you could estimate this by looking at the byte counter on the DLCI asuming F/R. Set up an FTP, clear counters, then start the FTP, when it completes look at the DLCI byte counter, a bit messy, but with a large file you should be able to get a reasonable idea.

Another way, look at the NetIQ stuff, they do some tools that measure response time and estimate available bandwidth,

http://www.netiq.com

 

[tbilan]

Look on the internet for a free program called GetIF. It's a SNMP program that along with doing a bunch of stuff it will graph interface statistics every 5 seconds. You can graph the subinterface for that DLCI even though on the "show interfaces" command you don't actually see the bytes in/out. You can see interface descriptions and statistics from walking OID .1.3.6.1.2.1.2.2.1 in GetIF. Take 30 mins to learn it and you'll use that program all the time.


Tom Bilan
TJBA, Inc.
CCNP, CCDP, MCSE & CNE