All Ban commands can be deactivated within the BanConfig.conf so this may not apply to your server depending on the settings that have been applied

When you ban someone you can ban by at least one of the following (You can ban by all three if you wish). Banning by a online player will kick the player from the server too.

If you wish to ban by all three, you can use the following command

ban <player - online>

This is the typical way to ban someone. This will ban someones account, therefore that person can join the server again, however they will need to be a different player. That is the only way around this ban and if your server is in online mode (which is should be) then unless they are buying more accounts, they will eventually run out of accounts to join with.

ban account <player - online or offline>

When joining anything online, you will have a IP address which is your house's name online. So by banning this IP in theory, no matter how many accounts they have, they cannot join back. However in reality there are a lot of issues on banning an IP.

The first one is that the IP is household. By banning the IP you are preventing all players at that house from joining. This doesn't sound too bad but if the person your banning is using a VPN, you don't actually ban there household, but ban the VPN server.

The second one is like your real name, you can change your IP (and some broadband providers will automaticity do this) however unlike changing your name, changing your IP is typically free.

ban ip <player - online>

or

ban ip <ip address - ipv4 or ipv6>

A Mac address is not unique to Apple computers but instead your computers ID. Banning this will ban the computer. This, like IP banning bans all accounts from that computer, however like IP banning also has some notes.

First of all, this bans the computer, not the house. So the banned player can change computer to then join again but most people don't have unlimited computers and unlike IP address, you can't easily change this address as it's built directly into the computer.

There are ways to change it in terms of how your server knows. If the banned user connects via a VPN provider who spoofs the Mac Address, then your only banning the mac address of the VPN)

ban mac <player>

If you wish to remove a ban from someone, you can by using the following commands

unban <player - offline>

The following command will unban based on the player name you banned. If you banned by the IP address when the player wasn't online then this will not work and you need to unban the ip address manually.