someone is botting/hacking and crash the server

hi, someone anonymousbot was in irc and he has bot who spams account and it crash server.
is any plugins for that or something else to do? this crash server and he has attacked now 1 day.
i had whitelist with 70 players and i miss really them. when he spam this, next time when try start server, it laggs so much. he spams maybe 50 times in second. he hacked my irc channel too .
when i came, he was op in irc and i wasnt anymore. he muted all my players.

and im running windows 7, with java build 29 maybe.
its non-hamachi whitelisted.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

start new irc mhmh

 

IP-ban him didnt work ?

 

Ban the IP - that might help. Also, is tere anything in your router settings or maybe firewall that lets you block a certain IP?

 

Your router might also be able to restrict the amount of packages 1 IP can send every second.
IP ban might work.