LAN surveilance

hello all,
I would like to know the best software for surveilance of my employees in my office using only my computer that's also Windows. All the computers are either using windows xp,2000 & 98. Can anybody tell me which is the best software for LAN surveilance like i wanna know which employee visit porno sites and other things. I hope to get the reply soon. Thanks

If you want to monitor the sites they visit you should use an HTTP proxy such as squid.

I know using proxy server we can monitor the websites visited. But i can't do that since all the network is working fine. If u know some other softwares then that will b gr8 and its in NAT.

I would agree with sahirh about using a proxy. The alternative is to use software that would need to be installed on each individual PC. This approach has its own problems. Using a proxy does not necessarily mean you have to alter your network. If you have a single point of access to the internet, which you do since you mentioned NAT, you could use a "transparent" proxy in between your network and gateway router which simply logs web site access.

Are you doing this as an admin or are you a regular user who can't make changes to the network.