OSPF MD5 Authentication (enable for interface)

Operation step:
 1. Config  OSPF authertication ,enable for interface
 2. Config MD5 key id , and authentication password


R1#
=====================================
hostname R1
!
interface Loopback0
 ip address 10.1.1.1 255.255.255.255
!
interface Loopback1
 ip address 10.2.2.2 255.255.255.255
!
interface Loopback2
 ip address 10.3.3.3 255.255.255.255
!
interface Serial1/0
 ip address 172.16.1.1 255.255.255.252
 encapsulation ppp
 ip ospf authentication message-digest
 ip ospf message-digest-key 1 md5 mykey
!
router ospf 1
 log-adjacency-changes
 network 10.1.1.1 0.0.0.0 area 0
 network 10.2.2.2 0.0.0.0 area 0
 network 10.3.3.3 0.0.0.0 area 0
 network 172.16.1.0 0.0.0.3 area 0
=====================================


 R2#
=====================================
 hostname R2
!
interface Loopback0
 ip address 10.4.4.4 255.255.255.255
!
interface Loopback1
 ip address 10.5.5.5 255.255.255.255
!
interface Loopback2
 ip address 10.6.6.6 255.255.255.255
!
interface Serial1/0
 ip address 172.16.1.2 255.255.255.252
 encapsulation ppp
 ip ospf authentication message-digest
 ip ospf message-digest-key 1 md5 mykey
!
router ospf 1
 log-adjacency-changes
 network 10.4.4.4 0.0.0.0 area 0
 network 10.5.5.5 0.0.0.0 area 0
 network 10.6.6.6 0.0.0.0 area 0
 network 172.16.1.0 0.0.0.3 area 0
===================================== 



R1#sh ip ospf int s1/0
Serial1/0 is up, line protocol is up
  Internet Address 172.16.1.1/30, Area 0
  Process ID 1, Router ID 172.16.1.1, Network Type POINT_TO_POINT, Cost: 64
  Transmit Delay is 1 sec, State POINT_TO_POINT
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
    Hello due in 00:00:06
  Supports Link-local Signaling (LLS)
  Cisco NSF helper support enabled
  IETF NSF helper support enabled
  Index 1/1, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 1, maximum is 1
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 1, Adjacent neighbor count is 1
    Adjacent with neighbor 10.6.6.6
  Suppress hello for 0 neighbor(s)
  Message digest authentication enabled
    Youngest key id is 1
R1#

R1#sh ip ospf nei
Neighbor ID     Pri   State           Dead Time   Address         Interface
10.6.6.6          0   FULL/  -        00:00:33    172.16.1.2      Serial1/0
R1#