Tool to monitor internet usage on a network?

[Tjalfe]

we have a small amount of computers on our work network, 7, I think. they are all connected through a switch, then a router to the internet. Is there any tools out there ( preferably free) which can be used to log how much traffic each computer sends to/from the internet, to help spot the heavy users? we have in 14 days had 95GB of traffic, which is our max, before paying overage fees, and to the best of my knowledge, we don't have any torrent users, though I would like a way to find out.. the same with finding out if one machine acts as a spam server of sorts.

thanks

Tjalfe

[MultimediaMan]

Smoothwall can do IP Bandwidth accounting in and out of the network by default. It won't tell you a thing about redirects within your network (Machine "A" connecting to Machine "B" and initiating connections to the internet from Machine "B" on behalf of Machine "A"), however.

If you give everyone a static IP address or a DHCP reservation, you can get a very clear picture of Traffic usage.

[VJ]

I use Ipfire, not sure if it has the exact same capabilities, but Smoothwall is not updated frequently...

[MultimediaMan]

Smoothwall just had a functionality update a couple of months ago: there have been no critical issues in quite a long time for it.

I just got a Smoothie running again primarily for content blocking...my kids are getting old enough to need more oversight.

[VJ]

I used Smoothwall before, but I needed support for a USB 3G modem. Recompiling the kernel to the latest version did the trick, but broke some functionality (but I didn't need that). AFAIK, the current version still uses an older kernel version.
I tested IPCop - didn't like the interface, Vyatta - too complex, M0n0wall - no 3G support, PfSense - no 3G support. This was some 5 months ago, and then switched to IPFire as it supported the modem out of the box and did what I want...

[LvR]

Netlimiter ?

[VJ]

I thought netlimiter doesn't allow you to view traffic from individual computers on the local network...

[Tjalfe]

Man, just noticed there had been responses.. talk about not paying attention.
smoothwall requires it to be the internet gateway, does it not?
we have a regular cablemodem/router combination, which I am thinking will not let me install smooth wall.
I was thinking back to the days of etherpeek, a program which could put the network card in promiscuous mode, snooping all packets on the network, and then, give me an idea much data from each machine went to the net.
if at all possible, I would prefer to not have to install something on all the computers, just one machine to monitor what is going on