3.4.1 Flags
nU: The route
is up
nG: The
router is to a gateway (router). If this flag is not set the
destination is directly connected
nH: The route is to a
host, that is the destination is a complete host address. If this flag is not set, the route is
to a
network, and the destination is a network address (net ID or net ID and
subnet ID)