Specify NAT methods
Use the --p2p-nat-method option to specify the NAT method. Options are NONE and UPNP.
You cannot change the NAT method while Teku is running. To change the NAT method restart the node with the --p2p-nat-method option.
UPnP
Specify UPNP to quickly allow inbound peer connections without manual router configuration. Use UPnP in home or small office environments where a wireless router or modem provides NAT isolation.
UPnP automatically detects if a node is running in a UPnP environment and provides port forwarding. UPnP might introduce delays during node startup, especially on networks without a UPnP gateway device.
tip
UPnP support is often disabled by default in networking firmware. If disabled by default, you must explicitly enable UPnP support.