Looking for a network monitor

[LittleNeutrino Veteran]

Ok so the company i work for has never really had a REAL IT department before however when i started i changed all of that. And i am finally getting to the point of implementing all of the new stuff. I was wondering if there was a Free software solution that would allow me to monitor Web traffic on our network to see what sites people were going to and what IP address or MAC Address for the computer that was going to what URL. is this even possible without installing anything on the other computers. If it matters one of the servers internally is also a DNS server however it is only telling computers to go to internally used websites (our intranet) would it be something that would be installed on that. Currently we have a SonicWall 300 Pro that i am using to Block traffic to adult sites and Social Networking pages however i am uncertain if that device will provide me with the information that i am looking for.

Thank you for any assistance anyone may be able to provide.

[sc302 Veteran]

ntop. http://www.ntop.org/download.html

squid proxy http://www.squid-cache.org/ <---monitor and block

[wrack]

We use Network Monitor 3.3.

[.Kompressor]

sure it is possible ....ordinary packet sniffers are good for troubleshooting network issues...example... wireshark.

....but the best stuff will cost you for the best visual results and displays packets, ip, mac, the works...you can see every site a user by ip/mac address, etc.. .goes too....also, monitor, email messages, msn & yahoo or bit torrent activity etc...

this is the kit you need to sit between your router(internet) and your internal switch or firewall. If you already have a smart switch like something from cisco it can monitor using the debug port... :) as traffic goes and comes from that switch to the internet...

Colasoft Capture enterprise.

I've used it and it is amazing at what it does...I haven't seen anything out of the box that works as easy as this....not sure if any opensource setups are this simple...haven't tried any......very neat graphically reports and graphs, total bandwidth/per ip user and allows to you take snapshots to measure activity per user etc.., logs for all kinds of things...We were just talking about it today in the office how good it is.

it's great....check out the video on the site...or try the trial.

http://www.colasoft.com/