A type 2 LSA only exists for multiaccess and non-broadcast multiaccess (NBMA) networks where there is a DR elected and at least two routers on the multiaccess segment. The type 2 LSA contains the router ID and IP address of the DR, along with the router ID of all other routers on the multiaccess segment. A type 2 LSA is created for every multiaccess network in the area.
The purpose of a type 2 LSA is to give other routers information about multiaccess networks within the same area.
The DR floods type 2 LSAs only within the area in which they originated. Type 2 LSAs are not forwarded outside of an area.
Type 2 LSAs are also referred to as network link entries.
As shown in the figure, ABR1 is the DR for the Ethernet network in area 1. It generates the type 2 LSA and forwards it into area 1. ABR2 is the DR for the multiaccess network in area 0. There are no multiaccess networks in area 2 and therefore, no type 2 LSAs are ever propagated in that area.
The link-state ID for a network LSA is the IP interface address of the DR that advertises it.