Internet Bandwidth Usage in Network 3

[netadmin06]

Hello, I have a Network with about 50 computers in a domain with a Windows 2003 DC. We have a T-1 line that half is used for voice and half for data. Lately someone is downloading and/or using alot of data from the Internet to the point where other pc's browsers take up to a minute before they load a page. Is there a program (preferably free) that shows me in an EASY way what computers are using the most INTERNET bandwidth? I need to find out who is doing all of the downloading or streaming radio etc. The program should show maybe like a network map of all PC's in network and how much Internet Bandwidth each pc is using so I can determine what is slowing down the Internet. Thanks so much

 

[lerdalt]

Almost any packet analyzer will give you pretty much what you are looking for. If you monitor the interface to the router, you can then watch the top talkers by bytes.

Are you using a Cisco router for the t1? I'm more familiar with Cisco, but I'm sure others can do the same thing, but you can enable netflow on the router and then get top-talkers information from it as well.

There are other commercial applications out there that can give even more statistics as well as help throttle conversations, for example, streaming video/audio.

 

[netadmin06]

I am using a Cisco 1700 series router however I do not manage it, it is being managed by our ISP. I guess that is a problem correct?

 

[lerdalt]

not really a problem..just means you don't get to use netflow.

best bet would be to setup a monitor port on the switch to watch the interface to the router. then use a sniffer to watch the conversations

 

[netadmin06]

lerdalt you mean I should monitor the port that the switch is using to connect to the T-1 line? ( port 23 in the switch is plugged in to the line that comes from the router with the internet signal) the switch is a Linksys Managed Switch SRW2048

 

[lerdalt]

yep, you got it. Not sure how to do it on a Linksys, but in Cisco it is called SPAN (Swith Port ANlyzer). I'm sure there is something similar in a Linksys managed switch.

What it will do is redirect all the packets that go through your port 23 to the monitor port where you can have a packet analyzer connected and then watch the traffic that way.

 

[netadmin06]

thanks lerdalt it is working great!

 

[gb0mb]

If your switches support SNMP I would consider setting up MRTG. This would give you bandwidth statistics on every port for each switch.

I make a main page that shows the uplink graph for each switch. With a quick look at that page i can call up the graphs for all ports on a switch and then narrow it down to the exact port pulling bandwidth.

Gb0mb

........99.9% User Error........
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[pcrequest]

http://www.smoothwall.org

firewall tracks usage by inside IP address and uses MRTG built-in and all setup. Pretty easy.

Also check out

http://www.paessler.com/prtg

Much easier if you are unfamiliar with snmp.

 

[netadmin06]

thanks allot pcrequest i will check them out