Connect to Valheim using Steam or crossplay networking

Identify which networking backend is running

Valheim dedicated servers can use Steam networking or the crossplay backend. Check the active startup arguments and server log rather than guessing from the server name. The -crossplay argument selects PlayFab networking. Without it, the documented dedicated-server configuration uses the Steam backend. Players need compatible game builds and any required mods before connection tests mean much.

Crossplay is the route for supported non-Steam clients joining a dedicated server. It does not make arbitrary mod packs compatible across platforms. If an installation depends on client mods that another platform cannot load, establish a separate supported configuration before promising that those players can join.

Use allocated ports rather than default examples

For Steam networking, Iron Gate documents a base UDP port and the next UDP port: the default example is 2456–2457. A hosted server must use ports actually allocated to it. If its configured base is different, the adjacent required port must also be allocated and reachable. Do not choose a neighbouring number that belongs to another service.

For a hosted CloudExa ~~help~~server, ~~guide.~~opening ports on your home router does not change the server’s network. Give support the server identifier and requested UDP allocation if the required pair is unavailable. Do not open every protocol or expose file transfer, administration or database ports to solve a game connection problem.

Test crossplay using its public connection method

The crossplay backend uses a PlayFab relay and does not require the same inbound router-forwarding arrangement as Steam networking. It still needs working outbound networking and access to its backend services. A host may reserve game ports for its configuration even when a relay carries the player traffic; keep those assigned settings consistent.

Use the public address and configured port, the join code, or the supported server list. Iron Gate specifically warns that local and loopback addresses cannot be used to connect through the crossplay backend. A failed localhost test therefore does not prove that a public crossplay server is down. Share join codes privately with intended players.

Separate visibility from actual reachability

The dedicated-server -public setting affects listing visibility. A hidden server may still accept a direct connection. First wait for the log to report its successful connection, then test with one external player. Confirm the player selected the right networking method and entered the port separately where the client requests it.

If Steam joins fail, compare the active port with the allocated UDP pair and report the exact timeout. If crossplay joins fail, record whether a fresh join code works and whether every platform fails or only one. Include timestamps and relevant log lines with secrets removed. Change one networking setting per test and retain the previous working configuration for rollback.