IP Bans can be evaded by using a VPN.
Getting a VPN Blocker on the server can cause issue for player who need to use a VPN to log onto the server.

 

He can easily evade an IP ban using a VPN, it would be effective to also disallow VPN's instead of just making sure that people using VPN's arn't bots. Also if admins somehow work out how to ban based on the computer ip then he could also evade this using a virtual computer, so yeah just ban vpn's