Icarus Dedicated Server Not Showing in Server Browser: Fixes

When an Icarus dedicated server does not show in Join Session, check three things first. The list starts on player hosted sessions, so flip the toggle in the top right to Dedicated Servers. The game client only downloads the first 2000 or so dedicated servers, so at busy times yours can simply be cut off; adding -MaxSearchResults=4000 to Icarus's Steam launch options raises that cap. And the server needs its game port (UDP 17777 by default) and query port (UDP 27015) reachable, with the same game version as the players. The rest of this guide covers each cause and how to tell them apart.

Fix 1: Flip the toggle to Dedicated Servers

This catches almost everyone once. From the orbital station:

1. Pick your character.
2. Select Join Session.
3. In the top right, switch the toggle from the player hosted list to Dedicated Servers.
4. Search for the server name and join.

RocketWerkz's own connecting to servers page lists the same steps. If no prospect is running, joining takes you to the Server Lobby, where you can pick or start a prospect. That is normal and means the connection works.

Fix 2: Raise the client's server list cap

Icarus asks Steam for a limited number of dedicated servers, around 2000, and there are often more than that online. When the list is full, your server may not be in the batch you got. The tell is that the list changes every time you refresh and your server appears once in a while.

The fix is on each player's PC, not the server:

1. In Steam, right click Icarus and choose Properties.
2. Under General, find Launch Options.
3. Enter -MaxSearchResults=4000.
4. Start the game and check the dedicated server list again.

This is a community fix shared on the Icarus Steam forums, and it is the first thing to try when the server shows for some players and not others.

Fix 3: Name the server with -SteamServerName

If you set SessionName in ServerSettings.ini and are searching for that name, you will not find it. RocketWerkz notes that SessionName currently does nothing. The name in the browser comes from the launch option:

IcarusServer-Win64-Shipping.exe -SteamServerName="Olympus Outpost" -PORT=17777 -QueryPort=27015 -Log

The name can be up to 64 characters. Search for the exact name you set there. If you left it out, the server shows under a default name that nobody is searching for.

Fix 4: Open the game and query ports

The query port is what makes the server appear in the list. If it is blocked, the server runs fine and nobody sees it. If the game port is blocked, players see it and fail to join.

On a home server:

1. Forward UDP 17777 and UDP 27015 on the router to the server PC. Our port forwarding guide covers it.
2. Allow IcarusServer-Win64-Shipping.exe through Windows Defender Firewall. See our Windows Firewall rules guide.
3. Make sure nothing else uses 27015. It is the default query port for many Steam games, so another server on the same PC may have it. Move one of them with -QueryPort=27016 and forward the new port.

On the Steam forums, a player whose server disappeared after an update found that changing the query port away from 27015 made it visible to friends again, so it is worth trying even when nothing else seems to use it.

Fix 5: Match the game version

Icarus gets frequent updates, and a server that has not updated hides from or rejects players on the new build. After every game update, update the server (SteamCMD app 2089300) and restart:

steamcmd +force_install_dir C:\icarus-server +login anonymous +app_update 2089300 validate +quit

Players on a different Steam branch than the server have the same problem. Everyone should be on the default branch unless the whole group and the server moved together. Our version mismatch guide has the general checklist.

Fix 6: The host cannot see their own server

If friends see and join the server but you cannot, and the server runs on your own network, that is a router limitation. Joining your own public address from inside the network needs NAT loopback (also called hairpinning). Some routers do not do it at all. Turn it on if your router has the option, or join from the LAN list if your server shows there.

If nobody outside can reach it either, check for carrier grade NAT with our guide on how to tell if you are behind CGNAT.

Fix 7: It shows up, but you cannot get in

Every key in that file is covered in Icarus dedicated server settings explained, and if you are bringing a world over from your PC, follow how to move an Icarus prospect to a dedicated server so the server loads it instead of a fresh one.

Still missing: two more things to try

• Change the Steam download region (Steam, Settings, Downloads) and restart Steam. Some players report the server list behaves differently afterwards.
• Restart the router, especially after changing port forwards. Some routers apply new rules only after a reboot.

When you would rather skip all of this

On an Icarus server from GamezServers, the server name and query port are panel settings and the server has its own public address with the ports open, so Fixes 3, 4 and 6 are already handled. Auto Update keeps it on the current build, ServerSettings.ini is in the file manager for the password and prospect options, and one click backups protect weeks of open world progress. Your players may still need the -MaxSearchResults launch option at busy times, since that cap is in the game client.

FAQ

Why is my Icarus server not in the server list?

Usually the toggle is still on player hosted sessions, the client's 2000 server cap cut it off, or the query port (UDP 27015) is blocked. Check those in that order.

What does -MaxSearchResults do in Icarus?

It raises how many dedicated servers the game downloads for the list. Add -MaxSearchResults=4000 to Icarus's launch options in Steam.

What ports does an Icarus dedicated server use?

UDP 17777 for the game and UDP 27015 for the Steam query by default, set with -PORT= and -QueryPort=.

Why does my Icarus server name not change?

SessionName in ServerSettings.ini does not work. Use the -SteamServerName= launch option.

Can Icarus players connect by IP?

The supported way in is the Dedicated Servers list in Join Session. Getting the server into that list is what the fixes above are for.