block local user to access a site
one of my local net colleagues just disrespect me. and since i have the computer which is used as a gateway to linux, and i know the root password, and i told the guy from my local net the respective ip address, now i just want to block it.
i believe it would be something like: block 192.168.0.28 88.231......
if this doesn't brake your moral code, then i need your help. thx in advance.