Enable Masquerade to allow port forwarding sudo firewall-cmd --permanent --add-masquerade Forward TFTP UDP port 69 to 6969 sudo firewall-cmd --permanent --add-port=69/udp sudo firewall-cmd --permanent --add-port=6969/udp sudo firewall-cmd --permanent --add-forward-port=port=69:proto=udp:toport=6969 sudo systemctl reload firewalld