Destination network

Destination network prefixes identify the networks known to a routing switch. When the routing switch receives a packet for routing, it matches the packet's destination address to a network prefix in the routing table and forwards the packet to the indicated gateway for that network. The prefix in the routing table defines how many leftmost contiguous bits to use when matching a packet's destination address to a destination network prefix. For example, a route table entry of


applies to all packets with a destination address for which the first 112 bits are


If a packet matches more than one routing table entry, the router uses the most specific route (the route with the longest prefix), which is assumed to be the most accurate for that packet. For example, for the packet destination listed below, both route table entries apply, but the route selected will be the 72-bit entry, because it is the more specific route.

Packet destination address:   2001:db8:0:1d5:a15::f:101/64
72-bit entry in route table:  2001:db8:0:1d5:a00::/72
64-bit entry in route table:  2001:db8:0:1d5::/64