+###--------------------------------------------------------------------------
+### Commands: mtu
+
+def cmd_mtu(args):
+ mtu, = (lambda mtu = '1500': (mtu,))(*args)
+ mtu = int(mtu)
+
+ blksz = C.gcciphers[conf['cipher']].blksz
+
+ index = conf['mac'].find('/')
+ if index == -1:
+ tagsz = C.gcmacs[conf['mac']].tagsz
+ else:
+ tagsz = int(conf['mac'][index + 1:])/8
+
+ mtu -= 20 # Minimum IP header
+ mtu -= 8 # UDP header
+ mtu -= 1 # TrIPE packet type octet
+ mtu -= tagsz # MAC tag
+ mtu -= 4 # Sequence number
+ mtu -= blksz # Initialization vector
+
+ print mtu
+