FiresGhettoNetworking

FiresGhettoNetworkMod

Updated for Valheim 1.0.

A comprehensive networking and server-authority mod for Valheim dedicated servers.

Combines compression, send-rate tuning, queue management, server-side simulation, RPC filtering,

and a per-client auto-tuner into a single drop-in plugin.

What this mod actually does

Valheim's vanilla networking is built around small, friend-group sessions. It works fine for 4 people and starts visibly straining around 8+. This mod replaces the bottlenecks:

• Server pushes harder and smarter, and with more headroom — bigger Steam send/recv buffers, higher max send rates, larger send queues, etc
• Server can run the world — with Server-Side Simulation on, the server loads the world around every player, drives spawns and raids, and manages zones
• Server sends less garbage and does less busywork — filtering on broadcast RPCs, closest-first ZDO sending when a connection backs up, AI LOD, WearNTear skips for unbreakable pieces.
• Client configs are tuned automatically — built-in auto-tuner sends test on first login, picks a performance tier, and applies the right values per machine. No more having to read and understand config values

You don't need to be a networking engineer to run a heavily-modded server with this. That's the point...

I'd rather you not touch your configs at all if you dont understand what they do.

What runs in each configuration

The mod is layered. Installing it does not turn everything on — most of the heavy server-authority work sits behind one master switch, and mob simulation sits behind another. Here is exactly what you get.

Server only (vanilla clients)

Everything here is server-side and needs nothing installed on your players' machines:

• Player limit + advertised player limit, crossplay backend selection
• Steam send rate / send buffer, send queue size, ZDO send rate — ⚠️ the Steam rate and buffer items reach Steam peers only; see Steam vs crossplay
• Per-peer adaptive send rate (each client ramps toward its own real link capacity)
• Bulk-transfer gate — raises the 20 KB queue limit inside every loaded ServerSync / ServerCharacters copy, so large config syncs on join stop stalling and dropping peers. This is one of the biggest real-world wins and it is entirely server-side
• Server-side auto-tune, plus all diagnostics and admin commands (fgn_headroom, fgn_flood, fgn_socketramp, fgn_comptest, fgn_zdoflood, fgn_links)
• World clock kept at real time — a slow server frame no longer lets the day, waves and timers fall behind (Keep World Clock At Real Time)
• Join grace — a player on a slow machine is not dropped after 30 seconds while a big world loads; the server waits up to 5 minutes for their first spawn (Join Grace Seconds, 0 = vanilla)
• Crossplay compression off the main thread — PlayFab's own compression runs on a worker thread, so one large message no longer freezes the server for up to a second (Fix PlayFab Compression Stalls)
• Everything under Server-Side Simulation, if you enable it (see below)

Server + client

Installing on both adds the client-side half:

• Deflate packet compression — negotiated per peer, so it only engages when both ends have the mod. A vanilla client simply never negotiates and stays uncompressed. ⚠️ Steam connections only — a crossplay peer never compresses even with the mod on both ends
• Client-side interpolation and prediction — smooths other players' movement
• Client auto-tune: zone-load batching, instantiation budget, receive-buffer sizing, destroy throttling
• HyperBoost receive side (also needs FiresSteamworksPatcher)
• Smooth server clock corrections (the boat damage fix) — every 2 seconds the server corrects each player's clock, and vanilla jumps the waves, the day and timers to match, which a boat with players aboard takes as slamming into the water. The mod eases those corrections in so nothing jumps or runs backwards (Smooth Server Clock Corrections, which replaces the old Fix Boat Damage From Server Time Sync). A ship is