How to enable the OSPF authentication within a specified area?
 

According to the figure above, enable OSPF authentication on Area 0.

Re: OSPF Area Authentication
 

Knowledge Points:

OSPF provides two types of authentication methods:

• Type 1 (text encryption): (config-if)#ip ospf authentication-key password

• Type 2 (MD5 encryption): (config-if)#ip ospf message-digest-key key_value md5 password

To enable the area authentication, do the followings:

1. Enable the able the area authentication in the routing process:
SW1(config-router)# area 0 authentication message-digest

2. Configure the encryption in the interfaces
SW2(config-if)# ip ospf message-digest-key 1 md5 netbrain