- Here is a configuration example for fixing Two OSPF Backbone (0) Areas
- Topoly Diagram
- Configurations
- Verification Commands
Here is a configuration example for fixing Two OSPF Backbone (0) Areas
Topoly Diagram
Configurations
ASBR1
interface Loopback11
ip address 11.11.11.11 255.255.255.255
!
interface FastEthernet0/0
ip address 192.168.12.1 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet0/1
ip address 201.23.23.1 255.255.255.0
ip ospf network point-to-point
duplex auto
speed auto
!
router ospf 100
router-id 1.1.1.1
log-adjacency-changes
area 3 virtual-link 3.3.3.3
network 11.11.11.11 0.0.0.0 area 0
network 192.168.12.1 0.0.0.0 area 0
network 201.23.23.1 0.0.0.0 area 3
!
Internal_Router1
interface Loopback22
ip address 22.22.22.22 255.255.255.255
!
interface FastEthernet0/0
ip address 192.168.12.2 255.255.255.0
duplex auto
speed auto
!
router ospf 100
router-id 2.2.2.2
log-adjacency-changes
network 22.22.22.22 0.0.0.0 area 1
network 192.168.12.2 0.0.0.0 area 0
ASBR2
interface FastEthernet0/0
ip address 172.16.34.1 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet0/1
ip address 201.23.23.2 255.255.255.0
ip ospf network point-to-point
duplex auto
speed auto
!
router ospf 100
router-id 3.3.3.3
log-adjacency-changes
area 3 virtual-link 1.1.1.1
network 172.16.34.1 0.0.0.0 area 0
network 201.23.23.2 0.0.0.0 area 3
Internal_Router2
interface Loopback44
ip address 44.44.44.44 255.255.255.255
!
interface FastEthernet0/0
ip address 172.16.34.2 255.255.255.0
duplex auto
speed auto
!
router ospf 100
router-id 4.4.4.4
log-adjacency-changes
network 44.44.44.44 0.0.0.0 area 1
network 172.16.34.2 0.0.0.0 area 0
!
Verification Commands
On ASBR1
ASBR1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
3.3.3.3 0 FULL/ - - 201.23.23.2 OSPF_VL0
2.2.2.2 1 FULL/BDR 00:00:36 192.168.12.2 FastEthernet0/0
3.3.3.3 0 FULL/ - 00:00:32 201.23.23.2 FastEthernet0/1
ASBR1#show ip ospf database
OSPF Router with ID (1.1.1.1) (Process ID 100)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 771 0x8000000A 0x00CF10 3
2.2.2.2 2.2.2.2 383 0x80000007 0x0034F9 1
3.3.3.3 3.3.3.3 1 (DNA) 0x80000006 0x002520 2
4.4.4.4 4.4.4.4 557 (DNA) 0x80000003 0x00341B 1
Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
172.16.34.1 3.3.3.3 573 (DNA) 0x80000001 0x006DC4
192.168.12.1 1.1.1.1 528 0x80000005 0x00BFEF
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
22.22.22.22 2.2.2.2 383 0x80000005 0x005780
44.44.44.44 4.4.4.4 553 (DNA) 0x80000001 0x002B50
201.23.23.0 1.1.1.1 1500 0x80000004 0x001D20
201.23.23.0 3.3.3.3 306 (DNA) 0x80000001 0x00E651
Router Link States (Area 3)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 773 0x80000009 0x002BE5 2
3.3.3.3 3.3.3.3 881 0x80000009 0x005CAB 2
Summary Net Link States (Area 3)
Link ID ADV Router Age Seq# Checksum
11.11.11.11 1.1.1.1 1256 0x80000004 0x007395
22.22.22.22 1.1.1.1 1502 0x80000004 0x00815A
44.44.44.44 3.3.3.3 1369 0x80000005 0x004B2F
172.16.34.0 3.3.3.3 1369 0x80000005 0x003419
192.168.12.0 1.1.1.1 1502 0x80000004 0x003986
On Internal_Router1
Internal_Router1#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
C 192.168.12.0/24 is directly connected, FastEthernet0/0
O IA 201.23.23.0/24 [110/2] via 192.168.12.1, 02:04:30, FastEthernet0/0
172.16.0.0/24 is subnetted, 1 subnets
O 172.16.34.0 [110/3] via 192.168.12.1, 01:54:54, FastEthernet0/0
22.0.0.0/32 is subnetted, 1 subnets
C 22.22.22.22 is directly connected, Loopback22
11.0.0.0/32 is subnetted, 1 subnets
O 11.11.11.11 [110/2] via 192.168.12.1, 02:01:48, FastEthernet0/0
44.0.0.0/32 is subnetted, 1 subnets
O IA 44.44.44.44 [110/4] via 192.168.12.1, 01:54:55, FastEthernet0/0
Internal_Router1#ping 44.44.44.44
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 44.44.44.44, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms
On ASBR2
ASBR2#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
1.1.1.1 0 FULL/ - - 201.23.23.1 OSPF_VL0
4.4.4.4 1 FULL/BDR 00:00:32 172.16.34.2 FastEthernet0/0
1.1.1.1 0 FULL/ - 00:00:38 201.23.23.1 FastEthernet0/1
Internal_Router2#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
O 192.168.12.0/24 [110/3] via 172.16.34.1, 01:55:51, FastEthernet0/0
O IA 201.23.23.0/24 [110/2] via 172.16.34.1, 02:06:25, FastEthernet0/0
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.34.0 is directly connected, FastEthernet0/0
22.0.0.0/32 is subnetted, 1 subnets
O IA 22.22.22.22 [110/4] via 172.16.34.1, 01:55:51, FastEthernet0/0
11.0.0.0/32 is subnetted, 1 subnets
O 11.11.11.11 [110/3] via 172.16.34.1, 01:55:51, FastEthernet0/0
44.0.0.0/32 is subnetted, 1 subnets
C 44.44.44.44 is directly connected, Loopback44
On Internal_Router2
Internal_Router2#ping 22.22.22.22
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 22.22.22.22, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms
If you think the document was helpful, please vote for it.