A router MUST allow a metric to be assigned to a static route for each routing domain that it supports.

The <Network-prefix> is administratively assigned so that its value will be unique in the routing domain to which the device is connected.

As such, it is allowed to maintain its forwarding database by listening to other routers in its routing domain.

Thus the LSP proxy egress for X becomes an "implicit peer" with each other LSR in the routing area or domain.

MOSPF routers can be mixed with OSPF routers within a routing domain, and they will interoperate in the forwarding of unicasts.

Some other possible uses are to identify the set of routers attached to a particular subnet, or the set of routers providing entry into a particular routing domain.

In some cases where MPLS is used to tunnel through a routing domain, it may not be possible to route to the source address of a fragmented packet at all.

In a CIDR routing domain, wherein classical IP network numbers are meaningless, the concept of an all-subnets-directed-broadcast is also meaningless.

AS path It may be useful to be able to assign a single preference value to all BGP routes (learned from the same routing domain) whose AS path "matches" any of a set of specified values.

It may be useful to be able to assign a single preference value to all BGP routes (learned from the same routing domain) whose AS path "matches" any of a set of specified values.