Summary of OSPF regional and interface Authentication

OSPF (Open Shortest Path First) is an Internal Gateway Protocol (IGP) used for Route decision-making in a single autonomous system (. Compared with RIP, OSPF is a link-state path protocol, while RIP is a distance vector routing protocol.
The link is another form of router interface. Therefore, OSPF is also known as the interface status routing protocol. OSPF establishes a link status database by notifying the status of network interfaces between routers, and generates a shortest path tree. Each OSPF router uses these Shortest Paths to construct a route table.
Authentication
For security reasons, we can enable the authentication function on the vrouters in the same OSPF region. Only the vrouters in the same region that have been authenticated can advertise route information to each other.
By default, OSPF does not use area verification. You can enable the authentication function in two ways: plain text authentication and Message Digest (md5) authentication. The authentication password transmitted by plain text authentication is identified by the Network detector, so it is not secure and is not recommended. The Digest (md5) authentication must encrypt the password before transmitting the authentication password. Therefore, we recommend that you use this method for authentication.
When using authentication, all vro interfaces in the region must use the same authentication method. To start identity authentication, you must configure a password for each vro interface in the region in router interface configuration mode.

1. If different types of authentication are enabled for the interface and region, the interface is strong! For example, two neighboring routers are interconnected through the serial port, and ciphertext authentication is enabled for the region at the same time. plaintext authentication is enabled on the serial port of one route, and no authentication is enabled on the serial port of the other. The neighbor relationship cannot be established.
2. If the same type of authentication is used for the interface and region, the region is strong! For example, if the zone enables ciphertext authentication, one interface also uses ciphertext authentication, and the other end cannot perform any authentication, and the neighbor relationship can be established.