.I path-mtu
between two peers is as specified. The default is 1500, which is very
commonly correct, but you should check using a tool such as
-.BR tracepath (8).
+.BR pathmtu (1).
Getting the MTU too big will lead to unnecessary fragmentation of
TrIPE's UDP datagrams; getting it too small will fail to utilize the
underlying network effectively. If in doubt, it's therefore better to