Adjacencies

Adjacencies are formed once OSPF has discovered its neighbors are used for exchanging routing information. Not every neighbor forms an adjacency.

OSPF forms adjacencies under the following conditions:

• Network connectivity is point-to-point.
• Network connectivity is achieved through a virtual link.
• A router is a DR.
• A router is a backup DR.
• A neighboring router is the backup DR.
• A neighboring router is the DR.

Virtual Links