Assetto Corsa Server Not Showing Up: Fixes That Work

If your Assetto Corsa server is not showing up in the in-game server list, the fix is almost always a combination of port forwarding, firewall rules, and the server browser’s filter settings. This article walks you through each step in order, from the most common cause (UDP port 9600 not being forwarded) to the less obvious ones (server name filters and NAT type).

Why Servers Disappear from the List

Assetto Corsa uses a master server list that your dedicated server registers with. When you start the server, it sends a heartbeat to the master server, which then lists it for all clients. If that heartbeat never arrives, or if the master server rejects it, your server stays invisible. The three most common reasons are:

• Ports not forwarded – the server can’t reach the master server or accept incoming connections.
• Windows Firewall blocking – the server executable is blocked from sending or receiving.
• Server browser filters – you’re filtering out your own server by name, region, or password settings.

Step 1: Forward the Correct Ports

Assetto Corsa uses two ports: TCP 8081 for the HTTP API and UDP 9600 for the game traffic. The UDP port is the one that matters for visibility. Log into your router’s admin page, find the port forwarding section, and create two rules:

1. UDP 9600 – forward to the local IP of the PC running the server.
2. TCP 8081 – forward to the same IP (optional but recommended for the web admin interface).

If you’re running the server on the same PC you’re playing on, you still need to forward the port to that PC’s local IP. After saving, restart the router and the server. To verify the port is open, use an online port checker tool while the server is running – if it says the port is closed, the forwarding rule is wrong or the firewall is still blocking.

Step 2: Allow the Server Through Windows Firewall

Windows Firewall often blocks the server executable silently. Add an inbound rule for both UDP 9600 and TCP 8081, and also allow the acServer.exe process (or the wrapper you use) for both private and public networks. To do this:

1. Open Windows Defender Firewall → Advanced Settings.
2. Click Inbound Rules → New Rule.
3. Choose Port, then UDP, and type 9600. Repeat for TCP 8081.
4. Also create a Program rule for the server executable if you prefer.

If you’re using a third-party launcher like Content Manager, remember it may spawn the server process differently – add the actual acServer.exe path, not the launcher.

Step 3: Check the Server Browser Filters

Sometimes the server is online and reachable, but you can’t see it because of filters. In the in-game server list, click the filter icon and make sure:

• Server name – clear any text in the search box.
• Region – set to “All” or your continent.
• Password – if your server is password-protected, it may be hidden unless you select “Show password protected” or similar.
• Version – ensure you’re not filtering by a different game version (e.g., 1.5 vs 1.6).

Also try clicking the refresh button and waiting 10–15 seconds. The master server list can be slow, especially during peak hours.

Step 4: Verify the Server Configuration File

A misconfigured server_cfg.ini can cause the server to start but not register. Open the file and check these lines:

• UDP_PORT=9600 – must match the forwarded port.
• TCP_PORT=8081 – same.
• REGISTER_TO_LOBBY=1 – this must be set to 1, otherwise the server never contacts the master server.
• NAME=Your Server Name – avoid special characters like | or : that can break the listing.

If you changed any of these, restart the server completely. Also make sure the server’s system/cfg folder has the correct track and car configurations – a server that fails to load a track will crash or never fully start.

Step 5: Check Router NAT and UPnP

Some routers have strict NAT or UPnP settings that interfere. If you have UPnP enabled, try disabling it and rely on manual port forwarding – sometimes UPnP creates conflicting rules. Conversely, if you’re using a router from your ISP, it might have a built-in firewall that blocks incoming UDP even after forwarding. In that case, try putting the server PC in the DMZ (demilitarized zone) temporarily to test – if the server appears, the router’s firewall is the culprit.

Step 6: Test with a Different Network

If you’re on a college campus, office network, or any network where you don’t control the router, port forwarding is usually impossible. In that case, the server will never appear in the public list. Options:

• Use a VPN with port forwarding (e.g., some VPN providers allow you to forward a port).
• Rent a dedicated game server from a hosting provider – they handle ports and visibility.
• Play over LAN only – if all players are on the same Wi-Fi, they can join via the LAN tab.

Frequently Asked Questions

Why does my server show up in LAN but not in the internet list?

LAN discovery uses broadcast packets that don’t require port forwarding. The internet list requires the master server to reach your server’s UDP port. If LAN works but internet doesn’t, the port forwarding or firewall is almost certainly the issue.

I forwarded the port but the online port checker says closed – what now?

Double-check that the server is actually running when you test. Also verify the local IP you forwarded to hasn’t changed – set a static IP on the server PC. If it’s still closed, your ISP might be blocking incoming connections (common with mobile hotspots or CGNAT). Contact your ISP or try a VPN.

Can I run the server on the same PC I play on?

Yes, but it uses resources. You’ll need to forward the port to your PC’s IP. Also, the server and client use different ports, so there’s no conflict. Just make sure your firewall allows both the server and the game.

Why does my server appear and then disappear after a few minutes?

This usually means the server is crashing or losing connection to the master server. Check the server log for errors – common causes are a missing track or car, or the server timing out due to a weak connection. Also check if your router’s NAT table is overflowing – a reboot usually helps.

Is there a way to see my server in the list without port forwarding?

If you’re on the same network as the server, you can join via the LAN tab. For internet play without port forwarding, you’d need a VPN that supports port forwarding or a dedicated host. There’s no way around the master server’s requirement for an open UDP port.

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