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Fixing StarRupture Eos HTTP Mismatch & Connection Errors

Star Rupture Guide โ€ข Updated Jan 19, 2026

Fixing StarRupture Eos HTTP Mismatch

As StarRupture uses Epic Online Services (EOS) for its backbone, many players encounter the "Eos HTTP Mismatch" error when trying to connect to private dedicated servers. This guide explains why this happens and how to fix it using tunneling or advanced network configuration.

๐Ÿšจ Common Symptoms

  • "Connection Failed: Eos HTTP Mismatch" popup.
  • Server appearing in the list but timing out on join.
  • "Source Address Verification Failed" in the server logs.
  • Infinite "Authenticating" screen.

What is Eos HTTP Mismatch?

This error occurs when the Epic Online Services backend detects a discrepancy between the IP address reporting the server to the master list and the IP address the client is trying to connect to. This is common with home-hosted servers or providers using complex load balancers.

Solution 1: Port Forwarding Verification

Most connection issues are due to incomplete port forwarding. Ensure both the Game and Query ports are open for **UDP**:

  • Game Port: 27015 (UDP)
  • Query Port: 27016 (UDP)
  • Internal Management: 7777 (UDP)

Solution 2: Public IP Tunneling

If you are behind a CGNAT (common with Starlink or Mobile Home Internet), you cannot port forward. In this case, you must use a **Tunneling Service** (like Playit.gg or Ngrok) to create a static entry point.

Tunneling Configuration Steps:

  1. Download a tunneling agent on your server.
  2. Map a UDP tunnel to your local 27015 port.
  3. In your ServerConfig.ini, you MUST set the PublicIP field to the tunnel's address: 
    [Network]
PublicIP=123.456.78.9 
ForceEOSIpBinding=true
  4. Restart the server. The EOS backend will now see the tunnel's IP as the "Source of Truth."

Solution 3: Fixing "Source Address Verification"

If the server logs show "Source Address Verification Failed," add the following to your Engine.ini (located in the saved folder):

[/Script/OnlineSubsystemUtils.IpNetDriver]
bVerifyNetworkDevice=false
MaxClientRate=100000
MaxInternetClientRate=100000

Warning: Overriding network device verification can slightly increase vulnerability to packet spoofing, but is often necessary for stable dedicated connections during Early Access.

๐ŸŒ Dedicated IPs

Using a Dedicated IP instead of a shared one (common in cheap hosting) resolve 90% of Eos Mismatch errors instantly.

๐Ÿ”ฅ Firewall Exceptions

Ensure StarRuptureServer.exe is whitelisted in Windows Firewall or your Linux IPtables. Blocked return packets are a major cause of auth timeouts.

Advanced Logging

To see exactly which IP is causing the mismatch, launch your server with the -log flag and look for lines containing LogEOSSDK. It will list the expected vs. actual IP addresses.

Frequently Asked Questions

Can I play without EOS?

Currently, no. StarRupture relies on EOS for cross-play and friend integration. A "LAN only" mode is requested but not yet implemented.

Does a VPN fix this?

Sometimes. If your ISP is throttling UDP packets, a VPN can help, but it often introduces more latency and its own Eos Mismatch issues.

Wait, I have the error on a hosted server!

If you're using a hosting provider, contact their support. They may need to update the PublicIP binding in their startup script to match their NAT configuration.

Next Steps

Zero Network Hassle: Supercraft's StarRupture servers come with Dedicated IPv4 addresses and pre-configured EOS bindings, completely eliminating the "Eos HTTP Mismatch" error for you and your players.

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