# ECO Server Won't Connect – Port 3000, Slg1 & Firewall

ECO dedicated server – connection failed? Port 3000/3001 UDP, slg1 file, mods & firewall – step-by-step troubleshooting.

**Quick answer:** ECO connection issues: **port 3000/3001 UDP**, matching **mod versions** and server fully started (2–5 min).

**If you landed here:** ECO shows "Connection failed", server not in list or mod mismatch on join.

## Related

- [Set up ECO server](/en/gameserver/eco/setup)
- [ECO performance](/en/gameserver/eco/server-improve-performance-and-fix-lag)