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OSPF - Not-So-Stubby Area (NSSA) + default information originate

In this 5th post about OSPF variations I will present NSSA with default information originate option. R8 and R9 can see area 0 prefixes and default gateway from R7 (O* N2 0.0.0.0/0)




R6#sh ip route
...

Gateway of last resort is not set

      10.0.0.0/8 is variably subnetted, 6 subnets, 2 masks
C        10.0.0.0/24 is directly connected, FastEthernet0/0
L        10.0.0.6/32 is directly connected, FastEthernet0/0
O IA     10.1.0.0/24 [110/2] via 10.0.0.7, 00:26:45, FastEthernet0/0
O IA     10.2.0.0/24 [110/3] via 10.0.0.7, 00:00:08, FastEthernet0/0
C        10.10.10.0/24 is directly connected, Loopback0
L        10.10.10.6/32 is directly connected, Loopback0
      172.16.0.0/24 is subnetted, 2 subnets
O E2     172.16.3.0 [110/200] via 10.0.0.7, 00:00:07, FastEthernet0/0
O E2     172.16.4.0 [110/200] via 10.0.0.7, 00:00:07, FastEthernet0/0
R6#sh ip ospf database database-summary

            OSPF Router with ID (10.10.10.6) (Process ID 10)

Area 0 database summary
  LSA Type      Count    Delete   Maxage
  Router        2        0        0
  Network       1        0        0
  Summary Net   2        0        0
  Summary ASBR  0        0        0
  Type-7 Ext    0        0        0
    Prefixes redistributed in Type-7  0
  Opaque Link   0        0        0
  Opaque Area   0        0        0
  Subtotal      5        0        0

Process 10 database summary
  LSA Type      Count    Delete   Maxage
  Router        2        0        0
  Network       1        0        0
  Summary Net   2        0        0
  Summary ASBR  0        0        0
  Type-7 Ext    0        0        0
  Opaque Link   0        0        0
  Opaque Area   0        0        0
  Type-5 Ext    2        0        0
      Prefixes redistributed in Type-5  0
  Opaque AS     0        0        0
  Non-self      5
  Total         7        0        0
R6#


R7#sh ip route
      10.0.0.0/8 is variably subnetted, 6 subnets, 2 masks
C        10.0.0.0/24 is directly connected, FastEthernet0/0
L        10.0.0.7/32 is directly connected, FastEthernet0/0
C        10.1.0.0/24 is directly connected, FastEthernet1/0
L        10.1.0.7/32 is directly connected, FastEthernet1/0
O        10.2.0.0/24 [110/2] via 10.1.0.8, 00:04:11, FastEthernet1/0
O        10.10.10.6/32 [110/2] via 10.0.0.6, 00:04:21, FastEthernet0/0
      172.16.0.0/24 is subnetted, 2 subnets
O N2     172.16.3.0 [110/200] via 10.1.0.8, 00:04:11, FastEthernet1/0
O N2     172.16.4.0 [110/200] via 10.1.0.8, 00:04:11, FastEthernet1/0
R7#sh ip ospf database database-summary

            OSPF Router with ID (10.1.0.7) (Process ID 10)

Area 0 database summary
  LSA Type      Count    Delete   Maxage
  Router        2        0        0
  Network       1        0        0
  Summary Net   2        0        0
  Summary ASBR  0        0        0
  Type-7 Ext    0        0        0
    Prefixes redistributed in Type-7  0
  Opaque Link   0        0        0
  Opaque Area   0        0        0
  Subtotal      5        0        0

Area 1 database summary
  LSA Type      Count    Delete   Maxage
  Router        3        0        0
  Network       2        0        0
  Summary Net   2        0        0
  Summary ASBR  0        0        0
  Type-7 Ext    3        0        0
    Prefixes redistributed in Type-7  0
  Opaque Link   0        0        0
  Opaque Area   0        0        0
  Subtotal      10       0        0

Process 10 database summary
  LSA Type      Count    Delete   Maxage
  Router        5        0        0
  Network       3        0        0
  Summary Net   4        0        0
  Summary ASBR  0        0        0
  Type-7 Ext    3        0        0
  Opaque Link   0        0        0
  Opaque Area   0        0        0
  Type-5 Ext    2        0        0
      Prefixes redistributed in Type-5  0
  Opaque AS     0        0        0
  Non-self      8
  Total         17       0        0
R7#



R8#sh ip route

Gateway of last resort is 10.1.0.7 to network 0.0.0.0

O*N2  0.0.0.0/0 [110/1] via 10.1.0.7, 00:02:17, FastEthernet1/0
      10.0.0.0/8 is variably subnetted, 6 subnets, 2 masks
O IA     10.0.0.0/24 [110/2] via 10.1.0.7, 00:04:16, FastEthernet1/0
C        10.1.0.0/24 is directly connected, FastEthernet1/0
L        10.1.0.8/32 is directly connected, FastEthernet1/0
C        10.2.0.0/24 is directly connected, FastEthernet0/0
L        10.2.0.8/32 is directly connected, FastEthernet0/0
O IA     10.10.10.6/32 [110/3] via 10.1.0.7, 00:04:16, FastEthernet1/0
      172.16.0.0/24 is subnetted, 2 subnets
O N2     172.16.3.0 [110/200] via 10.2.0.9, 00:03:25, FastEthernet0/0
O N2     172.16.4.0 [110/200] via 10.2.0.9, 00:03:25, FastEthernet0/0
R8#sh ip ospf database database-summary

            OSPF Router with ID (10.2.0.8) (Process ID 10)

Area 1 database summary
  LSA Type      Count    Delete   Maxage
  Router        3        0        0
  Network       2        0        0
  Summary Net   2        0        0
  Summary ASBR  0        0        0
  Type-7 Ext    3        0        0
    Prefixes redistributed in Type-7  0
  Opaque Link   0        0        0
  Opaque Area   0        0        0
  Subtotal      10       0        0

Process 10 database summary
  LSA Type      Count    Delete   Maxage
  Router        3        0        0
  Network       2        0        0
  Summary Net   2        0        0
  Summary ASBR  0        0        0
  Type-7 Ext    3        0        0
  Opaque Link   0        0        0
  Opaque Area   0        0        0
  Type-5 Ext    0        0        0
      Prefixes redistributed in Type-5  0
  Opaque AS     0        0        0
  Non-self      8
  Total         10       0        0
R8#



R9#sh ip route
Gateway of last resort is 10.2.0.8 to network 0.0.0.0

O*N2  0.0.0.0/0 [110/1] via 10.2.0.8, 00:03:11, FastEthernet0/0
      10.0.0.0/8 is variably subnetted, 5 subnets, 2 masks
O IA     10.0.0.0/24 [110/3] via 10.2.0.8, 00:04:19, FastEthernet0/0
O        10.1.0.0/24 [110/2] via 10.2.0.8, 00:04:19, FastEthernet0/0
C        10.2.0.0/24 is directly connected, FastEthernet0/0
L        10.2.0.9/32 is directly connected, FastEthernet0/0
O IA     10.10.10.6/32 [110/4] via 10.2.0.8, 00:04:19, FastEthernet0/0
      172.16.0.0/16 is variably subnetted, 3 subnets, 2 masks
C        172.16.3.0/24 is directly connected, FastEthernet1/1
L        172.16.3.9/32 is directly connected, FastEthernet1/1
R        172.16.4.0/24 [120/1] via 172.16.3.10, 00:00:01, FastEthernet1/1
R9#sh ip ospf database database-summary

            OSPF Router with ID (172.16.3.9) (Process ID 10)

Area 1 database summary
  LSA Type      Count    Delete   Maxage
  Router        3        0        0
  Network       2        0        0
  Summary Net   2        0        0
  Summary ASBR  0        0        0
  Type-7 Ext    3        0        0
    Prefixes redistributed in Type-7  2
  Opaque Link   0        0        0
  Opaque Area   0        0        0
  Subtotal      10       0        0

Process 10 database summary
  LSA Type      Count    Delete   Maxage
  Router        3        0        0
  Network       2        0        0
  Summary Net   2        0        0
  Summary ASBR  0        0        0
  Type-7 Ext    3        0        0
  Opaque Link   0        0        0
  Opaque Area   0        0        0
  Type-5 Ext    0        0        0
      Prefixes redistributed in Type-5  0
  Opaque AS     0        0        0
  Non-self      6
  Total         10       0        0
R9#


R10#sh ip route
Codes: L - local, 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, H - NHRP, l - LISP
       + - replicated route, % - next hop override

Gateway of last resort is not set

S     10.0.0.0/8 [1/0] via 172.16.3.9
      172.16.0.0/16 is variably subnetted, 4 subnets, 2 masks
C        172.16.3.0/24 is directly connected, FastEthernet1/1
L        172.16.3.10/32 is directly connected, FastEthernet1/1
C        172.16.4.0/24 is directly connected, Loopback0
L        172.16.4.10/32 is directly connected, Loopback0
R10# 
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