[Bacardi]

- Player maybe accidentally have a binded rcon command in they button and don't know this.
When spamming button multiple times in short time, server give IP ban.
Or they load custom configs which include rcon commands.
Never know.

- When connect to to server, you get automatically rcon address to that server.
And when you disconnect, waiting in main menu, you still have previous server rcon address.
In menu, if you hit rcon command in console multiple time, you get IP ban.

- With game server tool - program, for example hlsw.
You not need game, with program you can send rcon commands (accidentally ?).
Again, you send multiple rcon commands, server give IP ban.


IP bans are quite useless... because IP addresses changes.
You can change permament IP ban to temporary.

in csgo it's hidden cvar
sm_cvar sv_rcon_banpenalty 10


*edit
To Unban IP (you can use RCON)
removeip "xxx.xxx.xxx.xxx"
writeip

sm_unban "xxx.xxx.xxx.xxx"

*edit
Or remove from server configs:
exec banned_ip.cfg

reboot server