+.It Va PMTU Li = Ar mtu Po 1514 Pc Bq experimental
+This option controls the initial path MTU to this node.
+.It Va PMTUDiscovery Li = yes | no Po no Pc Bq experimental
+When this option is enabled, tinc will try to discover the path MTU to this node.
+After the path MTU has been discovered, it will be enforced on the VPN.