Whitelisting players

Whitelisting means only players on a list you control can join. It is the most effective single thing you can do for a small private server.

Enabling

From the console:

whitelist on

Or edit server.properties and set white-list=true, then restart.

Adding players

whitelist add <username>

Removing:

whitelist remove <username>

Listing:

whitelist list

Reload after editing the file

If you edit whitelist.json directly, run:

whitelist reload

Why bother

Public Minecraft servers get scanned constantly by botnets looking for unprotected ones. Whitelisting drops 100% of that noise — they connect, they're rejected, they move on. It is the cheapest security control in this entire docs section.