All OSPF protocol exchanges can be authenticated. This means that only trusted routers can participate in autonomous system routing. Nokia’s implementation of OSPF supports plain text and Message Digest 5 (MD5) authentication (also called simple password).
MD5 allows an authentication key to be configured per network. Routers in the same routing domain must be configured with the same key. When the MD5 hashing algorithm is used for authentication, MD5 is used to verify data integrity by creating a 128-bit message digest from the data input. It is unique to that data. Nokia’s implementation of MD5 allows the migration of an MD5 key by using a key ID for each unique key.
By default, authentication is not enabled on an interface.