Anno 1800 uses specific ports to communicate. If your router’s firewall is too strict, you’ll never see your friends’ lobbies. UDP: 18000, 18017, 3074, 3478, 4379, 4380, 27015, 27016
Ubisoft’s online services still try to route LAN traffic through their relay servers. The game doesn’t reliably fall back to direct IP / local broadcast.
represents the pinnacle of industrial-era strategy. However, since its launch, the multiplayer experience—specifically for those seeking the stability of Local Area Network (LAN) or consistent online sessions—has been a journey of technical hurdles and community-driven workarounds. The Desire for LAN and the "Online-Only" Reality
Multiplayer issues in often stem from synchronization errors (LR40) or network configurations that block the game's peer-to-peer communication. Since the game relies on Ubisoft Connect servers for matchmaking even on local networks, "true" LAN often still requires an active internet connection and specific port configurations.
Mastering Anno 1800 LAN Multiplayer: The Ultimate Fix and Setup Guide anno 1800 lan multiplayer fixed
issues, here are a few options depending on what specifically you fixed. Option 1: The "Desync & Connection" Fix
Right-click and any adapter that is not your primary Ethernet or Wi-Fi connection.
does not have a native "offline" LAN mode ; all multiplayer functionality requires an active internet connection to authenticate through Ubisoft Connect
Disable (also known as Client Isolation or Access Point Isolation), which explicitly blocks local wireless devices from talking directly to one another. Anno 1800 uses specific ports to communicate
Keep these disabled for the duration of your Anno 1800 gaming session. To ensure your next steps are successful, tell me:
Press the , type Firewall , and select Windows Defender Firewall .
This error is often a result of version mismatch or launcher issues, or a deeper connectivity bug. Make sure all players have the latest game updates and that Ubisoft Connect is fully patched. If the error persists, it is a known bug that has affected some players for years, sometimes without a clear workaround.
Right-click your active internet adapter (Ethernet or Wi-Fi) and select . The game doesn’t reliably fall back to direct
This open-source tool patches the game’s memory at runtime to:
, Ubisoft released a "Multiplayer Hotfix" in November 2025 to address lingering desyncs that appeared after minor system updates. Multiplayer Features
Disable any virtual adapters (e.g., Hamachi, RADMIN, VirtualBox, or active VPNs) if you are playing on a physical local network.