+.TP
+.B check
+Checks the various keyrings. Currently, it checks the
+.B master
+and
+.B keyring.pub
+files, and prints a report warning of keys which will expire soon. It
+is expected that this command be run against the master repository by
+.BR cron (8).
+Additional checking may added in the future.
+.TP
+.BR "mtu " [ \fIpath-mtu ]
+Write, as a decimal number on standard output, the recommended MTU for a
+TrIPE tunnel interface, given that the
+.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).
+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
+underestimate.