Whitelist, operators, and keeping control of your server

Turn the whitelist on first

Do this before you give the address to anyone. A server that is open for an afternoon while you set it up is a server that gets found.

From the panel console, or in game as an operator:

whitelist on
whitelist add SomePlayer
whitelist list

Names are added by lookup, so the player must exist. whitelist reload re-reads the file if you edited whitelist.json by hand. Turning the whitelist on does not kick anyone already connected; use kick if you need that.

Without a whitelist, the only thing between your world and the internet is luck. Minecraft servers are scanned constantly, and a fresh address is usually found within a day.

What op actually grants

op SomePlayer
deop SomePlayer

An operator can change the game mode, teleport, give themselves any item, ban other players, and run every command the server has. On Paper that includes commands added by plugins, which can mean world editing and file-level access through some plugins. Op is not “trusted friend”, it is “second owner”.

Give it to people you would trust with the password to the panel, and nobody else. For everyone else, use a permissions plugin such as LuckPerms and grant the specific commands they need. It is more setup for you once and far less risk afterwards.

server.properties has op-permission-level, which ranges from 1 to 4. Level 4 is the default and is full control. Lowering it to 2 or 3 is a reasonable hedge for a large friend group.

Leave online mode on

online-mode=true in server.properties makes the server verify every player against Mojang’s authentication servers. Turning it off lets anyone connect as any name, including yours. It is the single fastest way to lose a world.

If someone asks you to turn it off so they can join with a cracked launcher, the honest answer is that it opens the server to everyone who has ever heard of it, and there is no way to give that person access without giving it to everybody.

Moderating

kick SomePlayer Reason goes here
ban SomePlayer Reason goes here
ban-ip 203.0.113.9
pardon SomePlayer
banlist

Bans live in banned-players.json and banned-ips.json and survive restarts. Bear in mind that an IP ban on a home connection often stops being accurate within days, and can catch a housemate instead.

Before you need it

Two things make a griefing incident annoying rather than fatal:

• Backups. Take one manually before anything big, and know how to restore. See backups. The restore is the whole point; a backup you have never restored is a hope, not a plan.
• A rollback plugin. Something like CoreProtect logs who placed and broke every block and lets you undo one player’s work without losing everyone else’s. Install it before you need it, because it can only undo what it was running for. See adding plugins.

What we can and cannot do

We can restore a backup you took, help you read the logs, and deal with anything attacking the machine itself. We do not moderate servers, decide disputes between players, or act on reports about what happens inside your world. That is yours to run, which is also why it is yours to control.