Rust bans should be done with the player's SteamID64 where possible. Player names can change, but the SteamID64 stays tied to the Steam account.
You can run these commands from your server console or RCON tool.
Ban a player:
banid STEAMID64 "reason"
Replace STEAMID64 with the player's SteamID64. The reason is optional, but it is useful if you need to check the ban later.
Unban a player:
unban STEAMID64
Save the ban list:
server.writecfg
If the player is still banned after being unbanned, double-check the SteamID64 and check whether the ban is being handled by a plugin or external moderation tool.
