CISCO

The primary characteristic of a link-state protocol is a global topology database created when link states are exchanged between all neighbors within an area. There are link states advertised between all areas as well, and routes are installed in the routing table... NSSA and external routes have a lower preference than other previously mentioned route types. LSA Type 7 originate from an ASBR and include NSSA Type 1 route (N1) and NSSA Type 2 route (N2). N1 and N2 routes are advertised from an ASBR and transit not-so-stubby-area (NSSA). They are converted to Type 5 LSA at an ABR and flooded throughout the OSPF domain. The cost assigned to N1 is a default metric cost (20) + internal path cost from ASBR to destination. The cost assigned to N2 is a default metric cost (20) only and added at ASBR router redistribution point... Each network link is comprised of the local interface and a neighbor interface. The lowest cost assignable to an interface is 1 even though calculation could..