Short answer - ROSv6 and v7 don’t support /31 but there is a workaround with /32s (which I don’t recommend due to OSPF issues)
Long answer:
http://forum.mikrotik.com/t/point-to-point-31-addresses/29492/19
Short answer - ROSv6 and v7 don’t support /31 but there is a workaround with /32s (which I don’t recommend due to OSPF issues)
Long answer:
http://forum.mikrotik.com/t/point-to-point-31-addresses/29492/19