OSPF Authentication

OSPF Authentication using SHA256 Hashing
R1(config)# key chain NetAcad  #Assign a key chain name
R1(config-keychain)# key 1  #Assign a key chain  number
R1(config-keychain-key)# key-string CCNASkeystring #Assign the authentication key string
R1(config-keychain-key)#cryptographic-algorithm hmac-sha-256 #Configure the encryption algorithm to be used

Configure interfaces to use OSPF authentication
R1(config-if)# ip ospf authentication key-chain NetAcad

Verify 
R1# show ip ospf interface s0/0/0 
R2# show ip ospf neighbor