Network setup

xLimbo runs on its own Paper server behind your proxy, next to your main server. Two things connect it:

1. Your proxy sends players to xLimbo when the main server is unavailable.
2. main-server in xLimbo’s config names the server /join sends them back to.

Velocity

In velocity.toml, add xLimbo as a server and put it after your main server in try:

[servers]
main = "127.0.0.1:25566"
limbo = "127.0.0.1:25567"

try = ["main", "limbo"]

Players join main when it’s up and limbo when it isn’t. When main goes down with players on it, Velocity’s failover-on-unexpected-server-disconnect setting, which is on by default, moves them to the next server in try.

/join uses the BungeeCord plugin messaging channel, which Velocity supports while bungee-plugin-message-channel is true (the default).

BungeeCord and Waterfall

In the proxy’s config.yml, add xLimbo to servers and list it after your main server in the listener’s priorities:

servers:
  main:
    address: 127.0.0.1:25566
  limbo:
    address: 127.0.0.1:25567
listeners:
- priorities:
  - main
  - limbo

Point /join at your main server

Set main-server in plugins/xLimbo/config.yml to your main server’s name in the proxy’s config (main above):

main-server: "main"

Players can also be sent back on their own after a delay:

auto-join:
  enabled: true
  delay-seconds: 30
  message: "<green>Sending you to the server...</green>"

Test it

With a player online, stop your main server. They should land in xLimbo with a welcome message instead of being disconnected. Start it again and run /join.

Securing the proxy

/join works by sending the proxy a “Connect” plugin message. If forwarding isn’t secured, a player’s client can send that message too, and move itself around your network. xLimbo can’t prevent this; the proxy and servers must:

• Velocity: use modern forwarding (player-info-forwarding-mode = "modern") with a forwarding secret, and set it up on each backend server.
• BungeeCord: turn on IP forwarding, and firewall the backend servers so only the proxy can reach them.

Only set online-mode=false on a backend server when it sits behind a proxy with secure forwarding.