What Is KSP and How Does the DMP Multiplayer Mod Work?

Updated

KSP (Kerbal Space Program) is a physics-based spaceflight sandbox in which you build and fly spacecraft. DMP (DarkMultiPlayer) is a multiplayer mod for KSP that lets you see other players' craft and fly alongside them. To join, download and install the DMP client, then pick a server from the server list. To host, download the server, forward the DMP default port (6702) in your router, and optionally install the reporting plugin to appear on the public server list.

What KSP Is

Kerbal Space Program is a space program simulation game. Its core loop is:

  • Build a spacecraft from parts in the editor.
  • Fly it under a physics simulation — staging, thrust, gravity, orbital mechanics, and atmospheric drag all behave as modeled.
  • Fail and iterate — crashes and stranded kerbals are a normal part of the process.

That physics-driven sandbox is the base game. DMP does not change it; it adds other players to the same kind of world.

What DMP Adds

DMP is a multiplayer mod for Kerbal Space Program. According to the official DMP site, with it you can:

  • Watch other players' spacecraft — the site phrases this as watching other people's "Spacetape Art" while it crashes.
  • Fly with them — for example, to the moon (the Mun, in KSP terms).

In other words, instead of a single-player-only space program, you get a shared one where other players' vehicles and flights are visible to you.

How to Join a DMP Server

  1. Download the DMP client from the DMP website's Downloads section.
  2. Install it into your KSP setup.
  3. Open the server list and choose a server to join.

The server list is a first-class part of the site — the official page lists "Serverlist" in its main navigation, and the site notes there are lots of servers available there. If you would rather not depend on someone else's server, host your own (next section).

How to Host Your Own DMP Server

The official site gives three steps:

  1. Download the server from the DMP site.
  2. Forward the DMP default port (6702) in your router.
  3. Optional: if you want your server listed on the public server list, install the DMP Reporting Server-plugin.

Step 2 is the one people most often skip or get wrong. Port forwarding means telling your router to send incoming traffic on port 6702 to the machine running the DMP server. Without it, players outside your local network generally cannot reach you. The reporting plugin in step 3 is only about visibility on the server list — it is not required to run a server.

Voice Chat with Mumble

DMP runs its own Mumble server for VoIP. To use it:

  • Connect to d-mp.org using the default port 64738.
  • Download the Mumble client separately if you do not already have it (the DMP site links to it).

This is independent of the game connection — you join the Mumble server the same way you would join any other Mumble server.

Quick Reference

Task What you need Key detail
Join multiplayer DMP client + a server from the list Install client, then pick a server
Host a server DMP server download Forward default port 6702
Get listed publicly DMP Reporting Server-plugin Optional, on top of hosting
Voice chat Mumble client Connect to d-mp.org, port 64738

What to Check Before You Start

  • Version compatibility: DMP is a mod, so the client and server need to match your KSP version. Check the DMP site's Downloads section for what it currently supports rather than assuming any KSP build works.
  • Server rules and mods: individual servers in the server list may run their own mod sets or rules. Check a server's details before committing to it.
  • Hosting expectations: running a public server means keeping it updated and reachable; the port-forwarding and reporting-plugin steps above are the minimum the official site describes.