ipv6Prefix
1.3.6.1.4.1.8691.2.8.1.3.18
A prefix represents all of the network hosts
at one geographic location, in one building, or on
the same local area network. When a packet is sent
out over the network, the NPort will use the prefix
to check whether the TCP/IP host specified in the
packet is on the local network segment. If the address
is on the same network segment as the NPort, a connection
is established directly from the NPort. Otherwise, the
connection is established through the given default
gateway. Range is 1~128