This feature allows you to directly connect to peers over your local area network.
It can be found in Settings > Network > LAN Peers.
During normal operation, Fopnu automatically discards network traffic from private-IP ranges, such as 192.168.0.0/16 or 10.0.0.0/8. The LAN Peers feature allows you to specifically include peers on your local network, which provides a more direct and faster connection.
Simply type the IP address and port of each peer into the text box, one per line. Those peers must also do the same, putting your IP address in their config.
An alternate port for LAN use only can be specified. If so, make sure the other peers are using this port with your address in their configurations.
Also, an alternate interface can be specified. This is useful if you are using a VPN and already binding to it's interface directly in Settings > Network > Local Address. Your VPN interface will not work well for LAN traffic, so this alternate interface option can be very useful if you have a complicated network setup.
To find out what your own local IP address is, click the Help button in the main window, go to Diagnostics sub-menu, and select Network Locations. Near the very top of the readout, there will be a list of all local addresses. Look for ones that start with 192.168 or 10., or sometimes 169.254.