Download the full GNS3 files from below link.
https://docs.google.com/leaf?id=0B889ogd4ltI2OGZkMjE0YzMtNWJmOS00OGE5LTgwOTItYTMxMGI4Y2RkZWVm&hl=en&authkey=CNL66bUL
Here is lab topology.
Area 0 is backbone and Area 1 will be test for stub, NSSA and totally stub areas.
First configured all three routers with loopback and redistribute all routes to OSPF.
Here are the results and OSPF database to understand more about LSA types.
----------
After configuration all three routers with "router ospf 1" and adding all connected and loopback networks plus redistributed static routers, all can ping each other and routing tables will be shown as below.
R1
5.0.0.0/32 is subnetted, 1 subnets
C 5.5.5.5 is directly connected, Loopback0
6.0.0.0/32 is subnetted, 1 subnets
C 6.6.6.6 is directly connected, Loopback1
172.16.0.0/24 is subnetted, 1 subnets
O IA 172.16.10.0 [110/128] via 192.168.1.1, 00:17:28, Serial1/0
7.0.0.0/32 is subnetted, 1 subnets
C 7.7.7.7 is directly connected, Loopback3
10.0.0.0/24 is subnetted, 3 subnets
O E2 10.10.1.0 [110/20] via 192.168.1.1, 00:16:32, Serial1/0
O E2 10.10.2.0 [110/20] via 192.168.1.1, 00:16:32, Serial1/0
O E2 10.10.3.0 [110/20] via 192.168.1.1, 00:16:32, Serial1/0
C 192.168.1.0/24 is directly connected, Serial1/0
=================
R2
5.0.0.0/32 is subnetted, 1 subnets
C 5.5.5.5 is directly connected, Loopback0
6.0.0.0/32 is subnetted, 1 subnets
C 6.6.6.6 is directly connected, Loopback1
172.16.0.0/24 is subnetted, 1 subnets
O IA 172.16.10.0 [110/128] via 192.168.1.1, 00:17:28, Serial1/0
7.0.0.0/32 is subnetted, 1 subnets
C 7.7.7.7 is directly connected, Loopback3
10.0.0.0/24 is subnetted, 3 subnets
O E2 10.10.1.0 [110/20] via 192.168.1.1, 00:16:32, Serial1/0
O E2 10.10.2.0 [110/20] via 192.168.1.1, 00:16:32, Serial1/0
O E2 10.10.3.0 [110/20] via 192.168.1.1, 00:16:32, Serial1/0
C 192.168.1.0/24 is directly connected, Serial1/0
=============
R3
5.0.0.0/32 is subnetted, 1 subnets
C 5.5.5.5 is directly connected, Loopback0
6.0.0.0/32 is subnetted, 1 subnets
C 6.6.6.6 is directly connected, Loopback1
172.16.0.0/24 is subnetted, 1 subnets
O IA 172.16.10.0 [110/128] via 192.168.1.1, 00:17:28, Serial1/0
7.0.0.0/32 is subnetted, 1 subnets
C 7.7.7.7 is directly connected, Loopback3
10.0.0.0/24 is subnetted, 3 subnets
O E2 10.10.1.0 [110/20] via 192.168.1.1, 00:16:32, Serial1/0
O E2 10.10.2.0 [110/20] via 192.168.1.1, 00:16:32, Serial1/0
O E2 10.10.3.0 [110/20] via 192.168.1.1, 00:16:32, Serial1/0
C 192.168.1.0/24 is directly connected, Serial1/0
=============
Configuration Area 1 as stub by adding configuration in R1 and R2 using "area 1 stub"
R2 Warning Message.
R2(config-router)#area 1 stub
Warning: Router is currently an ASBR while having only one area which is a stub area
------------
R1 ABSR Route after stub.
5.0.0.0/32 is subnetted, 1 subnets
O E2 5.5.5.5 [110/20] via 192.168.1.3, 00:00:33, Serial1/0
6.0.0.0/32 is subnetted, 1 subnets
O E2 6.6.6.6 [110/20] via 192.168.1.3, 00:00:33, Serial1/0
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.10.0 is directly connected, Serial1/1
7.0.0.0/32 is subnetted, 1 subnets
O E2 7.7.7.7 [110/20] via 192.168.1.3, 00:00:33, Serial1/0
C 192.168.1.0/24 is directly connected, Serial1/0
---------------------------------------
R2 Route.
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.10.0 is directly connected, Serial1/0
10.0.0.0/24 is subnetted, 3 subnets
C 10.10.1.0 is directly connected, Loopback0
C 10.10.2.0 is directly connected, Loopback2
C 10.10.3.0 is directly connected, Loopback3
O IA 192.168.1.0/24 [110/128] via 172.16.10.1, 00:00:22, Serial1/0
O*IA 0.0.0.0/0 [110/65] via 172.16.10.1, 00:00:22, Serial1/0
--------------
R3 Route.
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.10.0 is directly connected, Serial1/0
10.0.0.0/24 is subnetted, 3 subnets
C 10.10.1.0 is directly connected, Loopback0
C 10.10.2.0 is directly connected, Loopback2
C 10.10.3.0 is directly connected, Loopback3
O IA 192.168.1.0/24 [110/128] via 172.16.10.1, 00:00:22, Serial1/0
O*IA 0.0.0.0/0 [110/65] via 172.16.10.1, 00:00:22, Serial1/0
------
Notice can't reach to external routers from Stub Area 10.10 network but ping can reach to external routes from Area 0 R3.
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.10.0 is directly connected, Serial1/0
10.0.0.0/24 is subnetted, 3 subnets
C 10.10.1.0 is directly connected, Loopback0
C 10.10.2.0 is directly connected, Loopback2
C 10.10.3.0 is directly connected, Loopback3
O IA 192.168.1.0/24 [110/128] via 172.16.10.1, 00:00:01, Serial1/0
O*IA 0.0.0.0/0 [110/65] via 172.16.10.1, 00:00:01, Serial1/0
R2#ping 5.5.5.5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 5.5.5.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 8/12/20 ms
-------
Check LSA routers in R1.
OSPF Router with ID (1.1.1.1) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 313 0x80000003 0x003B7C 2
3.3.3.3 3.3.3.3 263 0x80000004 0x007B30 2
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
172.16.10.0 1.1.1.1 313 0x80000002 0x00F739
Router Link States (Area 1)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 196 0x8000000A 0x00EE0F 2
2.2.2.2 2.2.2.2 184 0x8000000A 0x008B6E 2
Summary Net Link States (Area 1)
Link ID ADV Router Age Seq# Checksum
0.0.0.0 1.1.1.1 213 0x80000001 0x0093A6
192.168.1.0 1.1.1.1 215 0x80000005 0x004745
Type-5 AS External Link States
Link ID ADV Router Age Seq# Checksum Tag
5.5.5.5 3.3.3.3 511 0x80000002 0x00A4DA 0
6.6.6.6 3.3.3.3 511 0x80000002 0x007605 0
7.7.7.7 3.3.3.3 511 0x80000002 0x00482F 0
-------------
LSA routers in R2
OSPF Router with ID (2.2.2.2) (Process ID 1)
Router Link States (Area 1)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 185 0x8000000A 0x00EE0F 2
2.2.2.2 2.2.2.2 171 0x8000000A 0x008B6E 2
Summary Net Link States (Area 1)
Link ID ADV Router Age Seq# Checksum
0.0.0.0 1.1.1.1 202 0x80000001 0x0093A6
192.168.1.0 1.1.1.1 202 0x80000005 0x004745
========================
Configuration NSSA in Area 1
Route in R3
5.0.0.0/32 is subnetted, 1 subnets
C 5.5.5.5 is directly connected, Loopback0
6.0.0.0/32 is subnetted, 1 subnets
C 6.6.6.6 is directly connected, Loopback1
172.16.0.0/24 is subnetted, 1 subnets
O IA 172.16.10.0 [110/128] via 192.168.1.1, 00:01:33, Serial1/0
7.0.0.0/32 is subnetted, 1 subnets
C 7.7.7.7 is directly connected, Loopback3
10.0.0.0/24 is subnetted, 3 subnets
O E2 10.10.1.0 [110/20] via 192.168.1.1, 00:01:17, Serial1/0
O E2 10.10.2.0 [110/20] via 192.168.1.1, 00:01:17, Serial1/0
O E2 10.10.3.0 [110/20] via 192.168.1.1, 00:01:17, Serial1/0
C 192.168.1.0/24 is directly connected, Serial1/0
=============
Router in R1
5.0.0.0/32 is subnetted, 1 subnets
O E2 5.5.5.5 [110/20] via 192.168.1.3, 00:00:12, Serial1/0
6.0.0.0/32 is subnetted, 1 subnets
O E2 6.6.6.6 [110/20] via 192.168.1.3, 00:00:12, Serial1/0
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.10.0 is directly connected, Serial1/1
7.0.0.0/32 is subnetted, 1 subnets
O E2 7.7.7.7 [110/20] via 192.168.1.3, 00:00:12, Serial1/0
10.0.0.0/24 is subnetted, 3 subnets
O N2 10.10.1.0 [110/20] via 172.16.10.2, 00:00:12, Serial1/1
O N2 10.10.2.0 [110/20] via 172.16.10.2, 00:00:12, Serial1/1
O N2 10.10.3.0 [110/20] via 172.16.10.2, 00:00:12, Serial1/1
C 192.168.1.0/24 is directly connected, Serial1/0
--------
OSPF database in R1 include L7 NSSA types.
OSPF Router with ID (1.1.1.1) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 190 0x80000004 0x003F75 2
3.3.3.3 3.3.3.3 861 0x80000004 0x007B30 2
Summary Net Link States (Area 0)
Link ID ADV Router Age Seq# Checksum
172.16.10.0 1.1.1.1 910 0x80000002 0x00F739
Router Link States (Area 1)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 183 0x8000000E 0x00747B 2
2.2.2.2 2.2.2.2 183 0x8000000E 0x0011DA 2
Summary Net Link States (Area 1)
Link ID ADV Router Age Seq# Checksum
192.168.1.0 1.1.1.1 190 0x80000007 0x00CAB7
Type-7 AS External Link States (Area 1)
Link ID ADV Router Age Seq# Checksum Tag
10.10.1.0 2.2.2.2 198 0x80000001 0x00DBD4 0
10.10.2.0 2.2.2.2 198 0x80000001 0x00D0DE 0
10.10.3.0 2.2.2.2 198 0x80000001 0x00C5E8 0
Type-5 AS External Link States
Link ID ADV Router Age Seq# Checksum Tag
5.5.5.5 3.3.3.3 1108 0x80000002 0x00A4DA 0
6.6.6.6 3.3.3.3 1108 0x80000002 0x007605 0
7.7.7.7 3.3.3.3 1108 0x80000002 0x00482F 0
10.10.1.0 1.1.1.1 170 0x80000001 0x008E30 0
10.10.2.0 1.1.1.1 170 0x80000001 0x00833A 0
10.10.3.0 1.1.1.1 170 0x80000001 0x007844 0
===========
Router in R2
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.10.0 is directly connected, Serial1/0
10.0.0.0/24 is subnetted, 3 subnets
C 10.10.1.0 is directly connected, Loopback0
C 10.10.2.0 is directly connected, Loopback2
C 10.10.3.0 is directly connected, Loopback3
O IA 192.168.1.0/24 [110/128] via 172.16.10.1, 00:03:35, Serial1/0
-----------
LSA
R2#sh ip ospf database
OSPF Router with ID (2.2.2.2) (Process ID 1)
Router Link States (Area 1)
Link ID ADV Router Age Seq# Checksum Link count
1.1.1.1 1.1.1.1 250 0x8000000E 0x00747B 2
2.2.2.2 2.2.2.2 250 0x8000000E 0x0011DA 2
Summary Net Link States (Area 1)
Link ID ADV Router Age Seq# Checksum
192.168.1.0 1.1.1.1 258 0x80000007 0x00CAB7
Type-7 AS External Link States (Area 1)
Link ID ADV Router Age Seq# Checksum Tag
10.10.1.0 2.2.2.2 264 0x80000001 0x00DBD4 0
10.10.2.0 2.2.2.2 264 0x80000001 0x00D0DE 0
10.10.3.0 2.2.2.2 264 0x80000001 0x00C5E8 0
============
Result, ping can't reach to R3's extenal routes from NSSA area
R2#ping 5.5.5.5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 5.5.5.5, timeout is 2 seconds:
..
Success rate is 0 percent (0/2)
-----------
But area0 still can reach to external routers from NSSA area (not so stubby area).
----------------
Configuration Area 1 as totally stubby area as follows.
Totally Stub Area by adding "area 1 stub no-summary" in R1 and "area1 stub" in R2.
Note that totally stubby area is Cisco properity and it should be configured only in ABR
R1 router after configuration totally stubby area 1.
5.0.0.0/32 is subnetted, 1 subnets
O E2 5.5.5.5 [110/20] via 192.168.1.3, 00:10:37, Serial1/0
6.0.0.0/32 is subnetted, 1 subnets
O E2 6.6.6.6 [110/20] via 192.168.1.3, 00:10:37, Serial1/0
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.10.0 is directly connected, Serial1/1
7.0.0.0/32 is subnetted, 1 subnets
O E2 7.7.7.7 [110/20] via 192.168.1.3, 00:10:37, Serial1/0
C 192.168.1.0/24 is directly connected, Serial1/0
--------------
R2 routing table.
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.10.0 is directly connected, Serial1/0
10.0.0.0/24 is subnetted, 3 subnets
C 10.10.1.0 is directly connected, Loopback0
C 10.10.2.0 is directly connected, Loopback2
C 10.10.3.0 is directly connected, Loopback3
O*IA 0.0.0.0/0 [110/65] via 172.16.10.1, 00:10:26, Serial1/0
All have one default IA routes only.
---------------
R3 (Area 0 ) routing table
5.0.0.0/32 is subnetted, 1 subnets
C 5.5.5.5 is directly connected, Loopback0
6.0.0.0/32 is subnetted, 1 subnets
C 6.6.6.6 is directly connected, Loopback1
172.16.0.0/24 is subnetted, 1 subnets
O IA 172.16.10.0 [110/128] via 192.168.1.1, 00:10:26, Serial1/0
7.0.0.0/32 is subnetted, 1 subnets
C 7.7.7.7 is directly connected, Loopback3
C 192.168.1.0/24 is directly connected, Serial1/0
-----------
R3 can't ping any external routers from Stubby area 1 but R3 (stub area 1 can ping from both internal and external routes from Area 0)
--------
Not-So-Stubby Areas (NSSA): An OSPF stub area has no external routes in it. A NSSA allows external routes to be flooded within the area. These routes are then leaked into other areas. This is useful when you have a non-OSPF router connected to an ASBR of a NSSA. The routes are imported, and flooded throughout the area. However, external routes from other areas still do not enter the NSSA
--------
Here is summary of LSA types.
| Area | Restriction |
|---|---|
| Normal | None |
| Stub | Type 5 AS-external LSA NOT allowed |
| NSSA | Type 5 AS-external LSAs are NOT allowed, but Type 7 LSAs that convert to Type 5 at the NSSA ABR can traverse |
| Totally Stubby | Type 3, 4 or 5 LSAs are NOT allowed except the default summary route |
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