Controlling who can join — and who can wake your server

The whitelist limits who can join your server to a list of Minecraft usernames. On a Cobbly free server it does one more job: it decides who is allowed to wake the server up. That second job is why it is worth turning on even for a small server between friends.

Turn it on

1. Open the Players tab on the server page and pick the Whitelist list.
2. Add your own Minecraft username first.
3. Switch on Relay wake gate. It is the same setting as white-list in the Properties tab — changing one changes the other.
4. Add the Minecraft username of everyone else who should be allowed in.

You can do this while the server is running or stopped. While it is running, the change is sent to the server straight away as a command; while it is stopped, the list file is updated and the server reads it on the next start.

Two checks, not one

On a normal server the whitelist is checked once, when a player joins. On Cobbly it is checked twice:

• Before the server wakes. A sleeping server is not running at all — the address is answered by Cobbly’s front door, which looks up the whitelist before starting anything. A player who is not on it gets “You are not whitelisted on this server” and the server stays asleep.
• Once it is running. Minecraft’s own whitelist applies as usual: anyone not on the list is turned away with the standard “not white-listed” message.

The first check is what stops a stranger who learns your yourname.cobbly.net address from starting your server over and over, using up your slot and the capacity everyone else shares.

Waking needs a real Minecraft account

A username is only a claim, so before waking a whitelisted server Cobbly asks Mojang to confirm the player really owns that account — the same check a normal online-mode server does. Two things follow from that:

• The player must be logged in to the official launcher. If the check fails they see “Could not verify your Minecraft account” — logging out and back in to the launcher usually fixes it.
• Waking a whitelisted server needs Minecraft 1.8 or newer. Older clients are asked to update.

The name match at this stage ignores capital letters, so Steve and steve are the same entry.

Operators and bans

The same Players tab has three more lists. Operators gives a player admin commands, with a level from 1 (bypass spawn protection) to 4 (everything, including stopping the server). Banned Players and Banned IPs keep someone out, permanently or until a date you choose.

One thing to know: in Minecraft, operators can join a running server even when they are not on the whitelist — but they still cannot wake a sleeping Cobbly server unless they are on it. Add your ops to the whitelist too.

Kicking people who are already online

Turning the whitelist on does not throw out players who are already connected. If you want that, set enforce-whitelist=true in the Properties tab: from then on, whenever the whitelist is reloaded, anyone online who is not on it is disconnected.

Common problems

• You cannot get in yourself. Your own name is missing or misspelt. Add it from the Players tab — you do not need to be in the game to do that.
• A friend changed their Minecraft name. The wake check matches the name, so add their new one (and remove the old).
• A friend is on a cracked or non-premium client. They cannot pass the account check, so they cannot wake a whitelisted server. They can still join once someone with a premium account has woken it — if the server runs in offline mode. See below.

Offline-mode servers

If you have set online-mode=false, Minecraft does not verify usernames once the server is running, so its whitelist matches on the exact text of the name and is case-sensitive — add names exactly as players type them. The wake check described above still verifies the account, so on an offline-mode server the person who wakes it needs a premium account. Minecraft server offline mode covers the risks.

Not the same as panel access

The whitelist controls who can play. To let a friend manage the server itself — start and stop it, use the console, edit files — grant their Cobbly account access from the Access tab instead. Up to 5 people per server.