Configure the Null Authentication

1. Configure the OSPF authentication type as null authentication in SEFOS2.
   1. Type.

      SEFOS# configure terminal
      SEFOS(config)# interface vlan 1
      

   2. Delete the authentication key for message-digest authentication.

      SEFOS(config-if)# no ip ospf message-digest-key 0
      

   3. Enable null-digest authentication.

      SEFOS(config-if)# ip ospf authentication null
      

   4. Exit Interface Configuration mode.

      SEFOS(config-if)# exit
      

   5. Exit Configuration mode.

      SEFOS(config)# exit
      

2. Configure the OSPF authentication type as null authentication in SEFOS4.
   1. Type.

      SEFOS# configure terminal
      SEFOS(config)# interface vlan 1
      

   2. Delete the authentication key for message-digest authentication.

      SEFOS(config-if)# no ip ospf message-digest-key 0
      

   3. Enable null-digest authentication.

      SEFOS(config-if)# ip ospf authentication null
      

   4. Exit Interface Configuration mode.

      SEFOS(config-if)# exit
      

   5. Exit Configuration mode.

      SEFOS(config)# exit
      

3. Examine the adjacency formation between the neighbors.

   SEFOS# show ip ospf neighbor detail
   Neighbor 10.4.0.4, interface address 10.4.0.4
   In the area 0.0.0.0 via interface vlan1
   Neighbor priority is 1,  State is FULL/BACKUP, 5 state changes
   DR is 10.4.0.4 BDR is 10.4.0.2
   Options is 0x2