Each OSPF router uses only one Router-LSA to describe the status of local links in an area.

Link types described by a Router-LSA include P2P, P2MP, TransNet, and StubNet.

A Network-Summary-LSA describes the metric routing of an ABR to a destination network segment.

Routing information can be exchanged between a backbone area and a non-backbone area but never
between two non-backbone areas.