Can Combat Flight Simulator: WWII be played online multiplayer between UK and Australia?

Hi Kimo,

Yes, it can be done in principle, but the “how” depends on which Combat Flight Simulator you mean and what multiplayer method you’re trying. The big gotcha with the old Microsoft sims is that their multiplayer was designed around the services and network setups of the day, so across the public internet it usually needs a bit of help (and some router/firewall work).

Step 1 – Confirm which sim/version you both have
There’s a lot of confusion in names:

• Combat Flight Simulator (CFS1 – WWII Europe)
• Combat Flight Simulator 2 (WWII Pacific)
• Combat Flight Simulator 3 (WWII Europe)

If you can tell me exactly which one it is (what the title bar says when it runs, or what the box/CD says), I can be a lot more specific.

Step 2 – Make sure you’re both on the same build + same content
For any of these sims, mismatched versions/patch levels and mismatched mission files can stop you seeing each other or joining sessions.

• Verify you’re both running the same patched version (if applicable).
• Try a stock/default multiplayer setup first (no add-on aircraft/scenery/missions), just to prove the connection works.

Step 3 – Use the simplest connection method possible
Across UK ↔ Australia, “game room”/lobby style connections often fail now (those old matchmaking services are the first thing to break over time).

What normally works best is direct IP hosting (one hosts, the other joins by entering the host’s public IP). If the sim you’re using offers “Direct Connection” or similar, use that rather than relying on a lobby.

Step 4 – Router/NAT/firewall is usually the real problem
On Windows XP, even if the sim runs perfectly, multiplayer can fail because:

• Windows Firewall is blocking it (or only allowing it on the wrong network profile).
• The host’s router isn’t forwarding the required ports to the hosting PC (NAT).
• One or both of you is behind a stricter NAT that doesn’t allow incoming connections cleanly.

The usual test:

1. Decide who will host (pick the person with the “simpler” internet/router setup if possible).
2. Temporarily disable Windows Firewall on the host just for a quick test (or add an exception for the sim .exe).
3. Try again using direct IP.

If it suddenly works with the firewall off, you know you’re on the right track and can then add proper exceptions rather than leaving it off.

Step 5 – Don’t overlook the basics
These sound obvious, but they’ve bitten all of us:

• Both of you set the same session settings (aircraft era/mission type, etc.).
• Same mission file if you’re using a custom mission.
• Try a tiny “free flight / quick combat” style session first, then move to missions.

A few quick questions so I can point you to the exact fix

• Which Combat Flight Simulator is it exactly (CFS1 / CFS2 / CFS3)?
• When you “set up a multiplayer mission,” what fails specifically: can’t see the session, can’t join, or it connects then drops?
• Are you trying a “game room/lobby” option, or “direct IP”?
• Do either of you use a router (most do), and if so, who is hosting?
• Any error message at all, even a vague one?

Answer those and I’ll walk you through the right connection method and what to change on XP/firewall/router for that specific CFS version.