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“...are you allowing UDP Packets?”

Last reviewed: June 2, 2026

What are UDP Packets?​

The error “...are you allowing UDP packets to flow?” in FiveM usually pops up when the client cannot communicate with the server via UDP, which is critical for FiveM to establish and maintain a connection.

The error is basically asking:
&#xNAN;"Is UDP traffic on port 30120 (or your server port) allowed through both your server and your network?"

Without UDP, FiveM cannot complete the connection, even if the server is technically online.

Common Causes & Fixes​

Port Forwarding & Firewall​

Port 30120 (UDP) Not Open or Forwarded

See how to properly open your FiveM server ports here: Opening your Windows Ports

Firewall Blocking UDP Packets

Windows Firewall or iptables is rejecting UDP traffic.

  • (Windows) Open PowerShell as admin and run:
New-NetFirewallRule -DisplayName "FiveM UDP" -Direction Inbound -Protocol UDP -LocalPort 30120 -Action Allow
  • (Linux) Check with:
sudo ufw allow 30120/udp
Hosting Provider-Level Restrictions
  • Create a ticket via your client portal and verify that we do not have preset rules on your IP.

Internet or Routing Issues​

The client (player) can’t reach the server within the timeout period.
  • Restart router/modem.
  • Test with a different network or VPN.
  • Try connecting using direct IP (F8 console → connect <IP>:30120).
ISP routing delays, packet loss, blocking packets.

FiveM Sever Misconfiguration​

Incorrect endpoint_add_udp in server.cfg

endpoint_add_udp or endpoint_add_tcp in server.cfg is misconfigured or commented out.

  • Add or correct this line in server.cfg:
endpoint_add_udp "0.0.0.0:30120"
endpoint_add_tcp "0.0.0.0:30120"
  • Restart the FiveM server after changing.