Why Can’t You Join a Multiplayer Game in How to Fish

How to Fish uses a P2P multiplayer system, so players do not need to connect to a traditional game server. In theory, you and your friends should be able to join a multiplayer game as long as everyone has a working internet connection.

However, this does not always work as expected. A friend may create a room, but you receive an error when trying to join. Restarting the game and repeatedly attempting to connect may not solve the problem.

The issue is often related to connectivity between you and the host. The following checks can help identify and fix the problem.

Causes of Multiplayer Connection Errors

If you and your friends can access the internet normally but still cannot join a room, the common causes include:

• A strict NAT type;
• Double NAT on the router;
• CGNAT used by the ISP;
• Windows Firewall or security software blocking game traffic;
• An unstable Wi-Fi connection for the host;
• Different game versions or Mods;
• Poor public connectivity from the ISP.

How to Fix NAT Issues?

NAT allows devices on a local network to connect to the internet. It hides local IP addresses and determines whether external devices can initiate connections.

In P2P games, your NAT type can directly affect connections between players:

• Open NAT: Usually allows connections with most players;
• Moderate NAT: Usually works, but may have trouble connecting to some players;
• Strict NAT: More likely to cause failed connections, timeouts, or multiplayer errors.

Different platforms and routers may use different names, but the main issue is whether external players can reach the host’s game connection.

Method 1: Enable UPnP

UPnP allows the game and router to negotiate the required ports automatically, reducing the need for manual configuration.

1. Open your router’s administration page in a browser;
2. Sign in with the administrator account;
3. Find the UPnP settings;
4. Enable UPnP;
5. Save the settings and restart the router if necessary;
6. Restart Steam and How to Fish;
7. Ask the same player to host the room again, then test the connection.

Not every router supports UPnP. Even when UPnP is enabled, Double NAT or CGNAT may still prevent a successful connection.

If another router is connected behind your main router, the network may be using Double NAT. You can try setting one router to bridge mode or changing your personal router to access point mode.

Method 2: Use GearUP

Of course, improving NAT is not without automated options. For example, you can try GearUP, which can improve basic network connectivity issues and set up a dedicated How to Fish network channel to maintain stability.

The benefits are obvious: you do not need to go through various settings as with the previous method, and targeted optimizations can better fix connection problems. Generally, as long as you click boost in GearUP and then start the game, other players should be able to see you in their friends list and complete the connection.

Of course, we cannot guarantee 100% that GearUP will solve the problem. If you still fail to join multiplayer, try boosting again and check that each player's local network is functioning properly.

Check Network Stability

In a P2P game, the host usually handles important connection coordination and game data exchange. The host’s network quality can therefore affect every player.

If the host’s connection is unstable, the problem may involve more than simply failing to join the room. Players may also experience:

• A connection process that gets stuck;
• Frequent latency after joining;
• Character movement or actions being rolled back;
• Sudden player disconnections;
• Packet loss or connection interruptions for everyone.

Check the Host’s Connection First

Ask the host to complete the following checks:

1. Connect the computer with an Ethernet cable instead of using Wi-Fi;
2. Pause downloads, cloud synchronization, and video streaming;
3. Close applications that use upload bandwidth;
4. Restart the router and computer;
5. Test the connection with another online game or network tool;
6. If the router supports QoS, set the gaming device to high priority;
7. Check whether Windows is frequently disconnecting and reconnecting to the network.

Upload bandwidth also matters for P2P games. Even with a fast download connection, unstable upload performance can affect other players’ ability to join and remain connected.

Try a Different Host

If other players can access the internet normally but one player always fails to create a room, ask someone else to host the game.

After changing the host:

• Players who could not join may connect successfully;
• In-game latency and packet loss may change;
• You can determine whether the problem is limited to the original host’s network.

If everyone can join after changing the host, the original host may have a NAT, firewall, Wi-Fi, or ISP routing issue.

Some Smaller ISPs Have Poor Public Connectivity

Some smaller regional ISPs have limited peering resources or weaker connections to other networks. They may provide normal access to websites and video platforms but perform poorly when establishing P2P connections with other players.

Common signs include:

• You can connect only with some friends;
• Other online services work, but the P2P game does not;
• Changing the host noticeably improves the connection;
• Connection results vary at different times;
• The connection succeeds but still has frequent packet loss or latency.

Contact your ISP and ask about the following:

• Whether your connection uses CGNAT;
• Whether the ISP can provide a public IPv4 address;
• Whether incoming ports are restricted;
• Whether the connection type can be changed;
• Whether there are known connectivity issues between different providers.

If the ISP cannot improve the public connection, you can consider switching providers. However, this may require a new contract, line installation, or equipment and installation fees. The process can be inconvenient, and the total cost may be high.

Can I Host My Own Server?

When How to Fish uses P2P multiplayer, the host already performs some of the functions normally associated with a server. The player who creates the room usually coordinates the connection and shares game data with the other players.

However, this does not mean that you can create an independent dedicated server like those available for some online games. Dedicated Server support depends on whether the developer provides:

• An official server program;
• Dedicated Server files;
• An independent server configuration tool;
• Official server documentation;
• A third-party Mod that supports server hosting.

If the game does not provide these features, players usually have to use its built-in P2P rooms. Some Mods may claim to support dedicated servers, but their compatibility, stability, and security must be verified independently. They should not be assumed to work with the current game version.