I am running an ip-masq server with 2 ethernet cards(1 for cable modem). I have searched throughout the internet for a way to see what exactly is going across the network. I am looking for a way to see EXACTLY what files are being downloaded/etc by each user. So far all I have seen are variations of /proc/net/ip_conntrack, that only show the domain and protocol. Now I know that using a windows server, one can view exactly what are being downloaded, like this computer3 - http://www.server.org/stuff/file.fil or something like that. So how do I get that info from a linux server, and not just the dns.

are you saying you want to be able to see what files are being downloaded from a certain computer, or do you want to see the traffic on a network from a machine. If you want to see what files are being downloaded from a certain machine, you should be able to turn on some sort of logging but im not sure exactly what an ip-masq server is.

Why not just install Squid and run it in transparent mode... that way you can get your log of who what when and where, and save yourself a bit of bandwidth at the same time.

Other than that if i'm remembering right you could list the current connections with a switch iptables -L ... or was that for ipchains...i don't remember but it was something like that. I moved everything over to a proxy quite a long time back so haven't had the need for this in a while.