a site is taking down my server.

i own a banner exchange and there is a cheater.he is loading the ad multiple times hidden.in the afternoon it is too much for the server,cpu and memory max.
any suggestions to block the site?

 

you should check with your script if you have the possibility to do so. Or maybe a block via htaccess ^

 

Log into the server and block his ip?

 

Block the IP, if it's a DDos, then you might have to look at other solutions

 

Do some code modification

 

After notifying the account holder about their breach of your Terms of Service, cancel their account if they continue to disregard your TOS agreement.

 

Try this: How to block IP addresses with IPtables. Hope it helps.