1.区域认证
   a.简单明文认证
   进程下：area area-id authentication
   接口下：ip ospf authentication-key password
   b.MD5
   进程下：area area-id authentication message-digest
   接口下：ip ospf message-digest-key key-id md5 password
2.接口认证
   a.简单明文认证
   接口下：ip ospf authentication
            ip ospf authentication-key password
   b.MD5
   接口下：ip ospf authentication message-digest
            ip ospf message-digest-key key-id md5 password
3.区域虚链路认证
   a.简单明文认证
   进程下：area transit-area-id virtual-link router-id authentication authentication-key password
   b.MD5
   进程下：area transit-area-id virtual-link router-id authentication message-digest
                 area transit-area-id virtual-link router-id message-digest-key key-di md5 password