+.It Va UDPDiscovery Li = yes | no Po yes Pc
+When this option is enabled tinc will try to establish UDP connectivity to nodes,
+using TCP while it determines if a node is reachable over UDP. If it is disabled,
+tinc always assumes a node is reachable over UDP.
+Note that tinc will never use UDP with nodes that have
+.Va TCPOnly
+enabled.
+.It Va UDPDiscoveryKeepaliveInterval Li = Ar seconds Pq 9
+The minimum amount of time between sending UDP ping datagrams to check UDP connectivity once it has been established.
+Note that these pings are large, since they are used to verify link MTU as well.
+.It Va UDPDiscoveryInterval Li = Ar seconds Pq 2
+The minimum amount of time between sending UDP ping datagrams to try to establish UDP connectivity.
+.It Va UDPDiscoveryTimeout Li = Ar seconds Pq 30
+If tinc doesn't receive any UDP ping replies over the specified interval,
+it will assume UDP communication is broken and will fall back to TCP.