Please help

[matrixthe]

I want to block a certain user in my network who hijacks the ip addresses of registered users but if I try to block this user using ip address the legitimate user would also be blocked. Is there a way to block this user per se NetBIOS name wise? I tried to implement a policy using but I still can see the user using my connection. I am using NAT and port 80 is intercepted by Proxy Server, where shall I implement the policy. Help this user is getting off my nerves!

[genie]

You can try setting up a policy, where user MAC address should not be equal to the hijacker's one.

[matrixthe]

I feel cocky now that I blocked successfully this hijacker by using his MAC address! It feels so good! Wingate Rules!