В основном конфиге hlguard.cfg найдите секцию
//=====
// HLGuard mode
//=====
// Use ONE of these config files designed for InterNET, LAN and LEAGUE servers:
hlg_loadmode net // InterNET mode - Bans by UniqueID
//hlg_loadmode lan // LAN mode - Bans by IP address
// hlg_loadmode league // League mode - Only logs and displays cheats 

Для активации бана по IP нужно сделать вот так
//=====
// HLGuard mode
//=====
// Use ONE of these config files designed for InterNET, LAN and LEAGUE servers:
//hlg_loadmode net // InterNET mode - Bans by UniqueID
hlg_loadmode lan // LAN mode - Bans by IP address
// hlg_loadmode league // League mode - Only logs and displays cheats