OSPF Areas, Part 4, the Not-So-Stubby Area ~ CCNP, CCSP and CCIE Security Version 4 Training Institute in India- Delhi

Click here for Part 1 of the series or click here for Part 3 of the series.
Now it is time for us to examine yet another OSPF special area type – the Not-So-Stubby Area. I am sure you recall out topology from the previous parts, but here it is again:

When we left Area 11 in the last post, it was a Totally Stubby Area. This prevented LSA Types 3, 4, and 5 from entering the area, with the exception of the special default route (Type 3) generated by the Area Border Router.
The Not-So-Stubby Area (NSSA) allows us to bring in some redistributed routes into the stub area! Wow. I guess the area really isn’t that stubby at all. These redistributed routes propagate through the NSSA as Type 7, and are then converted on the ABR to Type 5. At least that is what we read in the RFCs. Let us see it in action at the command line!
I have removed the previous Totally Stubby configuration and I have placed the following command on all routers in Area 11 – area 11 nssa. After doing this, let us take a look at the OSPF database and routing table on R3:

R3#show ip ospf database

            OSPF Router with ID (3.3.3.3) (Process ID 1)

  Router Link States (Area 11)

Link ID         ADV Router      Age         Seq#       Checksum Link count
2.2.2.2         2.2.2.2         29          0x80000005 0x00A78B 1
3.3.3.3         3.3.3.3         28          0x80000004 0x0062CB 1

  Net Link States (Area 11)

Link ID         ADV Router      Age         Seq#       Checksum
192.168.1.3     3.3.3.3         28          0x80000001 0x00DACB

  Summary Net Link States (Area 11)

Link ID         ADV Router      Age         Seq#       Checksum
10.10.10.0      2.2.2.2         58          0x80000003 0x00E91B
172.16.10.0     2.2.2.2         58          0x80000003 0x0069F1

R3#show ip route

Gateway of last resort is not set

     172.16.0.0/24 is subnetted, 1 subnets
O IA    172.16.10.0 [110/21] via 192.168.1.2, 00:00:33, FastEthernet0/0
     10.0.0.0/24 is subnetted, 1 subnets
O IA    10.10.10.0 [110/20] via 192.168.1.2, 00:00:33, FastEthernet0/0
C    192.168.1.0/24 is directly connected, FastEthernet0/0
R3#

Notice how at this point,it looks just like a stub area. Type 4 and 5 LSAs have been filtered. Now, I will configure some loopbacks on R3, run RIP on them, and redistribute them into OSPF. Let us examine the OSPF database on R3 now:

R3#show ip ospf database

            OSPF Router with ID (3.3.3.3) (Process ID 1)

  Router Link States (Area 11)

Link ID         ADV Router      Age         Seq#       Checksum Link count
2.2.2.2         2.2.2.2         765         0x80000005 0x00A78B 1
3.3.3.3         3.3.3.3         10          0x80000005 0x0066C4 1

  Net Link States (Area 11)

Link ID         ADV Router      Age         Seq#       Checksum
192.168.1.3     3.3.3.3         764         0x80000001 0x00DACB

  Summary Net Link States (Area 11)

Link ID         ADV Router      Age         Seq#       Checksum
10.10.10.0      2.2.2.2         794         0x80000003 0x00E91B
172.16.10.0     2.2.2.2         794         0x80000003 0x0069F1

  Type-7 AS External Link States (Area 11)

Link ID         ADV Router      Age         Seq#       Checksum Tag
33.33.33.0      3.3.3.3         9           0x80000001 0x00F06E 0
44.44.44.0      3.3.3.3         11          0x80000001 0x0063DA 0
R3#

I guess the RFC did not lie to us! There they are – the Type 7 LSAs! Let us examine the OSPF database and IP routing table on R2 (the ABR):

R2#show ip ospf database

            OSPF Router with ID (2.2.2.2) (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         1120        0x80000002 0x0025E3 2
2.2.2.2         2.2.2.2         1023        0x80000003 0x007B5A 1

  Net Link States (Area 0)

Link ID         ADV Router      Age         Seq#       Checksum
10.10.10.1      1.1.1.1         1120        0x80000001 0x009476

  Summary Net Link States (Area 0)

Link ID         ADV Router      Age         Seq#       Checksum
192.168.1.0     2.2.2.2         1119        0x80000001 0x00F4CB

  Router Link States (Area 11)

Link ID         ADV Router      Age         Seq#       Checksum Link count
2.2.2.2         2.2.2.2         994         0x80000005 0x00A78B 1
3.3.3.3         3.3.3.3         241         0x80000005 0x0066C4 1

  Net Link States (Area 11)

Link ID         ADV Router      Age         Seq#       Checksum
192.168.1.3     3.3.3.3         996         0x80000001 0x00DACB

  Summary Net Link States (Area 11)

Link ID         ADV Router      Age         Seq#       Checksum
10.10.10.0      2.2.2.2         1025        0x80000003 0x00E91B
172.16.10.0     2.2.2.2         1025        0x80000003 0x0069F1

  Type-7 AS External Link States (Area 11)

Link ID         ADV Router      Age         Seq#       Checksum Tag
33.33.33.0      3.3.3.3         242         0x80000001 0x00F06E 0
44.44.44.0      3.3.3.3         242         0x80000001 0x0063DA 0

  Type-5 AS External Link States

Link ID         ADV Router      Age         Seq#       Checksum Tag
11.11.11.0      1.1.1.1         1171        0x80000001 0x0075AB 0
33.33.33.0      2.2.2.2         235         0x80000001 0x00A3C9 0
44.44.44.0      2.2.2.2         239         0x80000001 0x001636 0

R2#show ip route

Gateway of last resort is not set

     33.0.0.0/24 is subnetted, 1 subnets
O N2    33.33.33.0 [110/20000] via 192.168.1.3, 00:04:12, FastEthernet0/1
     172.16.0.0/24 is subnetted, 1 subnets
O       172.16.10.0 [110/11] via 10.10.10.1, 00:17:16, FastEthernet0/0
     10.0.0.0/24 is subnetted, 1 subnets
C       10.10.10.0 is directly connected, FastEthernet0/0
     11.0.0.0/24 is subnetted, 1 subnets
O E2    11.11.11.0 [110/20000] via 10.10.10.1, 00:04:12, FastEthernet0/0
C    192.168.1.0/24 is directly connected, FastEthernet0/1
     44.0.0.0/24 is subnetted, 1 subnets
O N2    44.44.44.0 [110/20000] via 192.168.1.3, 00:04:12, FastEthernet0/1
R2#

Holy LSAs Batman! This router has indeed converted the Type 7s to Type 5s and installed them in the routing table. Notice the N2 designations for NSSA area prefixes. Now let us examine R1 – an internal backbone router:

R1#show ip ospf database

            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         1704        0x80000002 0x0025E3 2
2.2.2.2         2.2.2.2         1609        0x80000003 0x007B5A 1

  Net Link States (Area 0)

Link ID         ADV Router      Age         Seq#       Checksum
10.10.10.1      1.1.1.1         1704        0x80000001 0x009476

  Summary Net Link States (Area 0)

Link ID         ADV Router      Age         Seq#       Checksum
192.168.1.0     2.2.2.2         1705        0x80000001 0x00F4CB

  Type-5 AS External Link States

Link ID         ADV Router      Age         Seq#       Checksum Tag
11.11.11.0      1.1.1.1         1755        0x80000001 0x0075AB 0
33.33.33.0      2.2.2.2         819         0x80000001 0x00A3C9 0
44.44.44.0      2.2.2.2         820         0x80000001 0x001636 0

R1#show ip route

Gateway of last resort is not set

     33.0.0.0/24 is subnetted, 1 subnets
O E2    33.33.33.0 [110/20000] via 10.10.10.2, 00:13:45, FastEthernet0/0
     172.16.0.0/24 is subnetted, 1 subnets
C       172.16.10.0 is directly connected, Loopback1
     10.0.0.0/24 is subnetted, 1 subnets
C       10.10.10.0 is directly connected, FastEthernet0/0
     11.0.0.0/24 is subnetted, 1 subnets
C       11.11.11.0 is directly connected, Loopback11
O IA 192.168.1.0/24 [110/20] via 10.10.10.2, 00:26:50, FastEthernet0/0
     44.0.0.0/24 is subnetted, 1 subnets
O E2    44.44.44.0 [110/20000] via 10.10.10.2, 00:13:45, FastEthernet0/0
R1#

This is what we would expect as well! This device just sees these prefixes as good, old-fashioned, Type 5 LSAs.
But wait, I think we have an issue now in this OSPF domain. Let us examine the routing table on R3:

R3#show ip route

Gateway of last resort is not set

     33.0.0.0/24 is subnetted, 1 subnets
C       33.33.33.0 is directly connected, Loopback33
     172.16.0.0/24 is subnetted, 1 subnets
O IA    172.16.10.0 [110/21] via 192.168.1.2, 00:18:43, FastEthernet0/0
     10.0.0.0/24 is subnetted, 1 subnets
O IA    10.10.10.0 [110/20] via 192.168.1.2, 00:18:43, FastEthernet0/0
C    192.168.1.0/24 is directly connected, FastEthernet0/0
     44.0.0.0/24 is subnetted, 1 subnets
C       44.44.44.0 is directly connected, Loopback44
R3#

We are not getting the Type 5 being generated on R1 as expected. But we are also not getting a default route from the ABR anymore. The default route is not automatic with the NSSA. All we need to do is modify the area 11 nssa command on R2 to area 11 nssa default-information-originate. Now everyone is happy, happy. Check out the routing table now on R3:

R3#show ip route
Gateway of last resort is 192.168.1.2 to network 0.0.0.0

     33.0.0.0/24 is subnetted, 1 subnets
C       33.33.33.0 is directly connected, Loopback33
     172.16.0.0/24 is subnetted, 1 subnets
O IA    172.16.10.0 [110/21] via 192.168.1.2, 00:21:51, FastEthernet0/0
     10.0.0.0/24 is subnetted, 1 subnets
O IA    10.10.10.0 [110/20] via 192.168.1.2, 00:21:51, FastEthernet0/0
C    192.168.1.0/24 is directly connected, FastEthernet0/0
     44.0.0.0/24 is subnetted, 1 subnets
C       44.44.44.0 is directly connected, Loopback44
O*N2 0.0.0.0/0 [110/1] via 192.168.1.2, 00:00:12, FastEthernet0/0
R3#

I hope you will join me for the next part of this blog series where we examine the Jumbo Shrimp of OSPF areas, the Totally Not-So-Stubby area!

About US

Network Bulls is Best Institute for Cisco CCNA, CCNA Security, CCNA Voice, CCNP, CCNP Security, CCNP Voice, CCIP, CCIE RS, CCIE Security Version 4 and CCIE Voice Certification courses in India. Network Bulls is a complete Cisco Certification Training and Course Coaching Institute in Gurgaon/Delhi NCR region in India. Network Bulls has Biggest Cisco Training labs in India. Network Bulls offers all Cisco courses on Real Cisco Devices. Network Bulls has Biggest Team of CCIE Trainers in North India, with more than 90% of passing rate in First Attempt for CCIE Security Version 4 candidates.

Biggest Cisco Training Labs in India
More than 90% Passing Rate in First Attempt
CCIE Certified Trainers for All courses
24x7 Lab Facility
100% Job Guaranteed Courses
Awarded as Best Network Security Institute in 2011 by Times
Only Institute in India, to provide CCIE Security Version 4.0 Training
CCIE Security Version 4 Training available
Latest equipments available for CCIE Security Version 4

Network Bulls Institute Gurgaon

Network Bulls Institute in Gurgaon is one of the best Cisco Certifications Training Centers in India. Network Bulls has Biggest Networking Training and Networking courses labs in North India. Network Bulls is offering Cisco Training courses on real Cisco Routers and Switches. Labs of Network Bulls Institute are 24x7 Available. There are many coaching Centers in Delhi, Gurgaon, Chandigarh, Jaipur, Surat, Mumbai, Bangalore, Hyderabad and Chennai, who are offering Cisco courses, but very few institutes out of that big list are offering Cisco Networking Training on real Cisco devices, with Live Projects. Network Bulls is not just an institute. Network Bulls is a Networking and Network Security Training and consultancy company, which is offering Cisco certifications Training as well support too. NB is awarded in January 2012, by Times, as Best Network Security and Cisco Training Institute for the year 2011. Network Bulls is also offering Summer Training in Gurgaon and Delhi. Network Bulls has collaboration with IT companies, from which Network Bulls is offering Networking courses in Summer Training and Industrial Training of Btech BE BCA MCA students on real Live projects. Job Oriented Training and Industrial Training on Live projects is also offered by network bulls in Gurgaon and Delhi NCR region. Network Bulls is also providing Cisco Networking Trainings to Corporates of Delhi, Gurgaon, bangalore, Jaipur, Nigeria, Chandigarh, Mohali, Haryana, Punjab, Bhiwani, Ambala, Chennai, Hyderabad.
Cisco Certification Exams are also conducted by Network Bulls in its Gurgaon Branch.
Network Bulls don't provide any Cisco CCNA, CCNP simulations for practice. They Provide High End Trainings on Real topologies for high tech troubleshooting on real Networks. There is a list of Top and best Training Institutes in India, which are providing CCNA and CCNP courses, but NB has a different image from market. Many students has given me their feedbacks and reviews about Network bulls Institute, but there were no complaints about any fraud from this institute. Network Bulls is such a wonderful place to get trained from Industry expert Trainers, under guidance of CCIE Certified Engineers.

CCIE Security Version 4

Cisco Finally updated CCIE Security Lab exam blueprint. WSA Ironport and ISE devices are added in CCIE Security Version 4 Lab Exam Syllabus Blueprint. In Updated CCIE Security Version 4 Syllabus blueprint, new technologies like Mobile Security, VoIP Security and IPV6 Security along with Network Security, are added. As in CCIE Security Version 3 blueprint, Cisco had focused on Network Security only, but now as per market demand, Cisco is looking forward to produce Internet gear Security Engineer, not only Network Security engineers.
In CCIE Security Version 4 Bluerpint, Lab Exam is going to be more interested than before. What is Difference in CCIE Security Version 3 and Version 4? Just go through the CCIE Security Version 4 Lab Equipment and Lab Exam Syllabus Blueprints and find out!

About NB

Network Bulls is Best institute for cisco certifications training in gurgaon. Network Bulls: A Complete CISCO Security Training Institute in Delhi/NCR, Gurgaon. Network Bulls provides Class Room, Online, One to One and Boot camp training on CCNA, CCNP, CCNA Security, CCNA Voice, CCSP, CCIE R&S, CCIE Security. Network Bulls is India's top CCIE (Cisco Certified Internetwork Expert) bootcamps, online classes and expert technical training Provider. Network Bulls provides ccna training in gurgaon. best ccnp training in gurgaon and bootcamp training for ccie written and lab certification in fast track, slow track and normal track for freshers and experienced candidates. NB is best ccie training institute in india. if anyone reallly interested doing quality training of cisco CCIE security Version 4, than i will recommend NB for CCIE Security Version 4 Training in India. CCIE Security Version 4 is highest level Certification offered by Cisco Systems, in Network Security track. All new devices of CCIE Security Version 4, are available in Network Bulls Gurgaon.

About Network Bulls Gurgaon

Best institute for ccna, ccnp, ccsp and ccie security version 4 course training in Delhi and Gurgaon.
Which is best ccsp institute in delhi? cisco certified security professional training in delhi ncr gurgaon. Nb provides world class top training for cisco security firewall in delhi ncr. Cisco CCIE certification exam lab asia's biggest lab training institution in new delhi gurgaon india. There are many institutes in India, who claims to provide Job Guarantee after CCNA even. There are some small institutes, who make fool of students with there cheap tricks and frauds. Some institutes in this field, do not have CCIE Certified trainers and racks available, but they claim to provide best training from other big institutes. Student should not take admission in such fraud and cheap institutes. Students can also give their valuable feedback, complaints and reviews about different institutes in our forums. But students should also be aware of wrong and unauthenticated feedback or complaints against great institutes like Network Bulls, Networkers Home and INE in some fake complaint forums, where no one is authenticating any comment or posts. Those wrong posts are written by some competitor institutes only. Those cheap and fraud institutes can't earn money and get admissions based on their results and infrastructure. They just write rubbish and wrong things on different forums against some good institutes and try to get admissions. A student who want to get refunds or good training or want to give feedback, can also go to consumer court and register a complaint against that fraud institute.
As per my experience Network Bulls and INE are both the best institutes of world.