OSPF Lab6 – Configuring OSPF NSSA Area and NSSA Totally Stub

Ensurepass

Objectives

1. Learn functions of type1, type2, type3, type4, type5, and type7 LSA in Totally Area.

2. Learn features of Area and Totally Stub Area

3. Learn the two area configuration methods

Note: Totally NSSA is CISCO private.

Lab Topology

111

Lab Steps

1. Configure IP addresses of every router, and use ping command to confirm the direct interface connectivity of every router.

2. Configure and RIP protocol, and use ping and show ip route command to confirm that protocol can work normally

3. Configure redistribution on P4S-R2 and P4S-R5 to complete lab requirements. Configure as follows:

P4S-R2(config)#router ospf 1

P4S-R2(config-router)#redistribute rip metric 200 subnets

P4S-R2(config-router)#exit

P4S-R2(config)#

P4S-R2(config)#router rip

P4S-R2(config-router)#redistribute ospf 1 metric 10

P4S-R2(config-router)#exit

P4S-R2(config)#exit

P4S-R5(config)#router ospf 1

P4S-R5(config-router)#redistribute rip metric 200 subnets

P4S-R5(config-router)#exit

P4S-R5(config)#

P4S-R5(config)#router rip

P4S-R5(config-router)#redistribute ospf 1 metric 10

P4S-R5(config-router)#exit

P4S-R5(config)#exit

4. Check P4S-R3 routing table and link status database

P4S-R3#show ip ospf database

OSPF Router with ID (172.16.255.5) (Process ID 1)

Router Link States (Area 1)

Link ID ADV Router Age Seq# Checksum Link count

172.16.255.1 172.16.255.1 534 0×80000005 0×008564 2

172.16.255.5 172.16.255.5 679 0×80000004 0×007390 4

172.16.255.9 172.16.255.9 672 0×80000003 0x00A42F 2

Summary Net Link States (Area 1)

Link ID ADV Router Age Seq# Checksum

172.16.255.8 172.16.255.9 662 0×80000001 0x005B1A

Summary ASB Link States (Area 1)

Link ID ADV Router Age Seq# Checksum

192.168.1.1 172.16.255.9 98 0×80000001 0x006E5C

Type-5 AS External Link States

Link ID ADV Router Age Seq# Checksum Tag

131.131.1.0 172.16.255.1 513 0×80000001 0x007BAA 0

131.131.2.0 172.16.255.1 513 0×80000001 0x0070B4 0

192.168.1.0 192.168.1.1 94 0×80000002 0x001FF5 0

192.168.2.0 192.168.1.1 94 0×80000002 0x0014FF 0

P4S-R3#

P4S-R3#show ip route

Gateway of last resort is not set

172.16.0.0/30 is subnetted, 3 subnets

C 172.16.255.0 is directly connected, Serial1/0

C 172.16.255.4 is directly connected, Serial1/1

O IA 172.16.255.8 [110/128] via 172.16.255.6, 00:07:46, Serial1/1

131.131.0.0/24 is subnetted, 2 subnets

O E2 131.131.1.0 [110/200] via 172.16.255.1, 00:00:30, Serial1/0

O E2 131.131.2.0 [110/200] via 172.16.255.1, 00:00:30, Serial1/0

O E2 192.168.1.0/24 [110/200] via 172.16.255.6, 00:00:30, Serial1/1

O E2 192.168.2.0/24 [110/200] via 172.16.255.6, 00:00:30, Serial1/1

P4S-R3#

Because area1 routes violate stub area requirements, i.e. stub area cannot have features of ASBR routers. Thus in this lab we use NSSA configuration to reduce the size of P4S-R3 routing table.

5. Configure area1 as NSSA area on P4S-R4.

P4S-R4(config)#router ospf 1

P4S-R4(config-router)#area 1 nssa default-information-originate

P4S-R4(config-router)#exit

P4S-R4(config)#

6. Configure as follows on P4S-R3:

P4S-R3(config)#router ospf 1

P4S-R3(config-router)#area 1 nssa

P4S-R3(config-router)#exit

P4S-R3(config)#exit

P4S-R3#

7. Configure as follows on P4S-R2:

P4S-R2(config)#router ospf 1

P4S-R2(config-router)#area 1 nssa

P4S-R2(config-router)#exit

P4S-R2(config)#exit

P4S-R3#

8. Check again P4S-R3 routing table and link status database

P4S-R3#show ip route

Gateway of last resort is 172.16.255.6 to network 0.0.0.0

172.16.0.0/30 is subnetted, 3 subnets

C 172.16.255.0 is directly connected, Serial1/0

C 172.16.255.4 is directly connected, Serial1/1

O IA 172.16.255.8 [110/128] via 172.16.255.6, 00:01:10, Serial1/1

131.131.0.0/24 is subnetted, 2 subnets

O N2 131.131.1.0 [110/200] via 172.16.255.1, 00:01:10, Serial1/0

O N2 131.131.2.0 [110/200] via 172.16.255.1, 00:01:10, Serial1/0

O*N2 0.0.0.0/0 [110/1] via 172.16.255.6, 00:01:10, Serial1/1

P4S-R3#

The following shows link status database of P4S-R3

P4S-R3#show ip ospf database

OSPF Router with ID (172.16.255.5) (Process ID 1)

Router Link States (Area 1)

Link ID ADV Router Age Seq# Checksum Link count

172.16.255.1 172.16.255.1 314 0×80000007 0x0027BA 2

172.16.255.5 172.16.255.5 314 0×80000008 0x0011E8 4

172.16.255.9 172.16.255.9 450 0×80000005 0x004C7D 2

Summary Net Link States (Area 1)

Link ID ADV Router Age Seq# Checksum

172.16.255.8 172.16.255.9 850 0×80000002 0x00FE6F

Type-7 AS External Link States (Area 1)

Link ID ADV Router Age Seq# Checksum Tag

0.0.0.0 172.16.255.9 850 0×80000001 0x00C464 0

131.131.1.0 172.16.255.1 318 0×80000001 0x00213D 0

131.131.2.0 172.16.255.1 318 0×80000001 0×001647 0

P4S-R3#

9. Check routing table of P4S-R2 and P4S-R3

P4S-R2#show ip route

Gateway of last resort is 172.16.255.2 to network 0.0.0.0

172.16.0.0/30 is subnetted, 3 subnets

C 172.16.255.0 is directly connected, Serial1/1

O 172.16.255.4 [110/128] via 172.16.255.2, 00:07:26, Serial1/1

O IA 172.16.255.8 [110/192] via 172.16.255.2, 00:07:26, Serial1/1

131.131.0.0/24 is subnetted, 2 subnets

R 131.131.1.0 [120/1] via 131.131.2.2, 00:00:06, Serial1/0

C 131.131.2.0 is directly connected, Serial1/0

O*N2 0.0.0.0/0 [110/1] via 172.16.255.2, 00:07:26, Serial1/1

P4S-R2#

The following shows routing table contents of P4S-R1:

P4S-R1#show ip route

Gateway of last resort is 131.131.2.1 to network 0.0.0.0

R 172.16.0.0/16 [120/10] via 131.131.2.1, 00:00:28, Serial1/1

131.131.0.0/24 is subnetted, 2 subnets

C 131.131.1.0 is directly connected, Loopback0

C 131.131.2.0 is directly connected, Serial1/1

R* 0.0.0.0/0 [120/10] via 131.131.2.1, 00:00:28, Serial1/1

P4S-R1#

10. Use ping command on P4S-R1 to test default route efficiency:

P4S-R1#ping 192.168.2.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.2.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 288/384/432 ms

P4S-R1#

11. In order to simplize routing table of routers in area1, we use Totally NSSA features to configure area 1.

12. Configure Totally NSSA area features based on NSSA, we only need to configure on P4S-R4 as follows:

P4S-R4(config)#router ospf 1

P4S-R4(config-router)#area 1 nssa no-summary

P4S-R4(config-router)#exit

13. Check again P4S-R3 routing table and link status database:

P4S-R3#show ip route

Gateway of last resort is 172.16.255.6 to network 0.0.0.0

172.16.0.0/30 is subnetted, 2 subnets

C 172.16.255.0 is directly connected, Serial1/0

C 172.16.255.4 is directly connected, Serial1/1

131.131.0.0/24 is subnetted, 2 subnets

O N2 131.131.1.0 [110/200] via 172.16.255.1, 00:20:24, Serial1/0

O N2 131.131.2.0 [110/200] via 172.16.255.1, 00:20:24, Serial1/0

O*IA 0.0.0.0/0 [110/65] via 172.16.255.6, 00:02:10, Serial1/1

P4S-R3#

P4S-R3#show ip ospf database

OSPF Router with ID (172.16.255.5) (Process ID 1)

Router Link States (Area 1)

Link ID ADV Router Age Seq# Checksum Link count

172.16.255.1 172.16.255.1 1504 0×80000007 0x0027BA 2

172.16.255.5 172.16.255.5 1504 0×80000008 0x0011E8 4

172.16.255.9 172.16.255.9 1640 0×80000005 0x004C7D 2

Summary Net Link States (Area 1)

Link ID ADV Router Age Seq# Checksum

0.0.0.0 172.16.255.9 396 0×80000001 0x0070FF

Type-7 AS External Link States (Area 1)

Link ID ADV Router Age Seq# Checksum Tag

0.0.0.0 172.16.255.9 66 0×80000002 0x00C265 0

131.131.1.0 172.16.255.1 1508 0×80000001 0x00213D 0

131.131.2.0 172.16.255.1 1508 0×80000001 0×001647 0

P4S-R3#

14. Check routing table of P4S-R1 and P4S-R2, and use ping command to confirm routes

P4S-R2#show ip route

Gateway of last resort is 172.16.255.2 to network 0.0.0.0

172.16.0.0/30 is subnetted, 2 subnets

C 172.16.255.0 is directly connected, Serial1/1

O 172.16.255.4 [110/128] via 172.16.255.2, 00:23:09, Serial1/1

131.131.0.0/24 is subnetted, 2 subnets

R 131.131.1.0 [120/1] via 131.131.2.2, 00:00:17, Serial1/0

C 131.131.2.0 is directly connected, Serial1/0

O*IA 0.0.0.0/0 [110/129] via 172.16.255.2, 00:04:46, Serial1/1

P4S-R2#

P4S-R1#show ip route

Gateway of last resort is 131.131.2.1 to network 0.0.0.0

R 172.16.0.0/16 [120/10] via 131.131.2.1, 00:00:13, Serial1/1

131.131.0.0/24 is subnetted, 2 subnets

C 131.131.1.0 is directly connected, Loopback0

C 131.131.2.0 is directly connected, Serial1/1

R* 0.0.0.0/0 [120/10] via 131.131.2.1, 00:00:13, Serial1/1

P4S-R1#

P4S-R1#ping 192.168.2.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.2.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 336/454/528 ms

P4S-R1#

15. Finally, go to P4S-R5 to check whether type 7 LSA on P4S-R3 is transformed to type 5 LSA.

P4S-R5#show ip ospf database

OSPF Router with ID (192.168.1.1) (Process ID 1)

Router Link States (Area 0)

Link ID ADV Router Age Seq# Checksum Link count

172.16.255.9 172.16.255.9 338 0×80000004 0x005DC2 2

192.168.1.1 192.168.1.1 767 0×80000004 0×002753 2

Summary Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum

172.16.255.0 172.16.255.9 81 0×80000002 0x002C10

172.16.255.4 172.16.255.9 1337 0×80000002 0x0081F6

Type-5 AS External Link States

Link ID ADV Router Age Seq# Checksum Tag

131.131.1.0 172.16.255.9 1761 0×80000001 0x0085DA 0

131.131.2.0 172.16.255.9 1761 0×80000001 0x007AE4 0

192.168.1.0 192.168.1.1 767 0×80000003 0x001DF6 0

192.168.2.0 192.168.1.1 767 0×80000003 0×001201 0

P4S-R5#

16. Lab finished.

Hope to helpful for you!





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