[MPLS] OSPF Super Backbone Area (2)

 

<목적>

1. Super Backbone Area와 동시에 Area 0는 없애기. (Area0는 2개 이상은 Area가 있는 경우 반드시 있어야 함)

2. Area 0가 없는데 OSPF 정상작동 가능한가?

 

<조건>

R1 - R4 는 Area 1, R2 - R5 는 Area 2, R3 - R6 은 Area 3

R1, R2, R3은 Super Backbone Area에 속한 라우터

 

<R4>

R4는 Area 1에 속해 있으며, 1.1.5.5와 1.1.6.6으로 Ping 가능

R4는 1.1.5.5, 1.1.6.6 모두 LSA type 3으로 광고받고 있음

R4#show ip ospf database
 
            OSPF Router with ID (1.1.4.4) (Process ID 1)
 
                Router Link States (Area 1)
 
Link ID         ADV Router      Age         Seq#       Checksum Link count
1.1.1.1         1.1.1.1         553         0x80000001 0x00DC1D 1
1.1.4.4         1.1.4.4         552         0x80000003 0x00C40A 2
 
                Net Link States (Area 1)
 
Link ID         ADV Router      Age         Seq#       Checksum
1.1.14.4        1.1.4.4         552         0x80000001 0x000C02
 
                Summary Net Link States (Area 1)
 
Link ID         ADV Router      Age         Seq#       Checksum
1.1.5.5         1.1.1.1         520         0x80000001 0x00CFD1
1.1.6.6         1.1.1.1         491         0x80000001 0x00BAE4
1.1.25.0        1.1.1.1         553         0x80000001 0x00C0DB
1.1.36.0        1.1.1.1         553         0x80000001 0x00474A
 
                Type-5 AS External Link States
 
Link ID         ADV Router      Age         Seq#       Checksum Tag
4.4.4.4         1.1.4.4         1026        0x8000000C 0x00D3A7 0
R4#
R4#ping 1.1.5.5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1.1.5.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms
R4#ping 1.1.6.6
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 1.1.6.6, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms
R4#
 

각 라우터 모두 Area1, 2, 3에 속해있다.

R1#show run | b router ospf
router ospf 1 vrf company1
 router-id 1.1.1.1
 redistribute bgp 1 subnets
 network 1.1.14.1 0.0.0.0 area 1
 
R2#show run | b router ospf
router ospf 1 vrf company1
 router-id 1.1.2.2
 redistribute bgp 1 subnets
 network 1.1.25.2 0.0.0.0 area 2
 
R3#show run | b router ospf
router ospf 1 vrf company1
 router-id 1.1.3.3
 redistribute bgp 1 subnets
 network 1.1.36.3 0.0.0.0 area 3
 
R4#show run | b router ospf
router ospf 1
 router-id 1.1.4.4
 redistribute connected subnets
 network 1.1.4.4 0.0.0.0 area 1
 network 1.1.14.4 0.0.0.0 area 1
 
R5#show run | b router ospf
router ospf 1
 router-id 1.1.5.5
 network 1.1.5.5 0.0.0.0 area 2
 network 1.1.25.5 0.0.0.0 area 2
 
R6#show run | b router ospf
router ospf 1
 router-id 1.1.6.6
 network 1.1.6.6 0.0.0.0 area 3
 network 1.1.36.6 0.0.0.0 area 3