MicroNugget: Cisco OSPF Areas & LSA Types Explained | CBT Nuggets

In this video, CBT Nuggets trainer Jeremy Cioara explains Open Shortest Path First (OSPF) areas and Link State Advertisement (LSA) types. This is a blisteringly fast introduction to OSPF Areas and LSA types, crucial and complicated topics if you're dealing with OSPF configurations.

If you're dealing with OSPF configurations, you're dealing with Areas and LSAs.

When you begin with OSPF configurations, you must create Area 0. Some businesses never grow beyond this so-called backbone area. But as the business begins to grow and you begin adding more routers, your routing table can get pretty unruly.

If there are too many routes, too many changes with networks going up and down, or processor cycles getting wasted, it’s important to break into multiple areas.

In Link State Protocol, all routers in the area must have the same link-state database. The only way to hide routes or do route summarization is to break into multiple areas.

Different areas include Stubby, Totally Stubby and Not-So-Stubby Areas. Yes, that's actually what they're called.

Stub area is where you have an area that’s limited in what information can receive. Cisco allows for totally stubby areas which makes traffic highly efficient. A not-so-stubby area camouflages external routes for the sake of expediency.

LSAs interact with the traffic and only some areas permit different LSAs. See which with Jeremy's explanation.

0:15: Backbone area, explained
0:55: Standard areas and stub areas
1:40: Cisco's totally stubby areas
2:15: Not-so-stubby areas
3:10: LSAs, Type 1 through 5
4:30: Which areas allow LSAs, and which

Start learning with CBT Nuggets:

[TheFearize]

crazy, i've just spend like 3 hours studying this and you just show it to me in 5 minutes... Give this man a medal!

[chriswhite]

This five minute video did a lot better than two chapters in the Cisco books. Great work.

[YesHotMandu]

"I'm gonna sit down now, and breathe in a brown paper bag" Golden. :)
Thanks Jeremy!

[ihateyourusernames]

Not only did you explain so much in so little time, but you did it without saying 'uh' or 'um' once. That's damn impressive.

[gunnertwin]

I understood it perfectly, it's not meant to be viewed by absolute beginners but by people that already know them and just want a quick refresh. Excellent job.

[nimahel]

Thanks for this video, it is the most helpful and straightforward way to explain areas and LSA types! Most every other source including official Cisco press make it so convoluted, videos like these are a blessing!

[BigJwlz]

I appreciate this fast explanation style. It helps me get the material sooner so I can move on to other subject matter. I can always play it again if I miss something.

[sadjidalebid]

I've been watching videos of 30 min explaining this concept and didn't understand like i did with this one, thank youuu.

[requemao]

I had to watch it twice in a row, but those were the most effective 11 minutes I've spent on CCNP. Kudos to Jeremy.

[linsturnbow]

That was excellent! You did a great job at conveying the concepts clearly in the most succinct way possible. Thank you!

[MustafaFekaiki]

I was amazed how you explained in just 5 minutes and I was studying with some video tutorial trying to explain it for hours . Cisco even make it very unclear .
Thank you very much .

[klausrenz]

This was the fastest and clearest Explaination of the LAS Types :) What others try to explain in 1 Hour got summarized and optimized in 5 minutes. Good job.

[dg-hughes]

This was well done. When I first started learning about LSAs it was so dry and boring I thought I'd die from the dullness. This video clearly explained what LSAs are and did it in a short time, a mark of a good teacher.

[ekotv]

Exactly what i needed.
I have to learn 500 pages and do a lot of exams aspart of my preparation to my final exam, such videos are perfect for me 🙂

[cbtnuggets]

We are glad you enjoyed this MicroNugget and we want them to do exactly that! Thanks for the feedback.

[username]

kept repeating a nugget for days regarding LSAs. This is the first time i understood it! Micronuggets work! Thanks Jeremy!

[nevetm]

This is the best OSPF video the Internet has ever been blessed with. Awesome work Jeremy!

[mohamed]

The magic OSPF Areas summary which reflect great knowledge and experience, thanks jermy for that nuggets

[isendel]

Jeremy I love all your videos. Keep up the good work. You rock. If I may be allowed to add a few lines to your masterful and fun method of teaching.

LSA & Area Types Relationship:

Stub = Block 4 & 5 LSA
NSSA = Blocks type 5 LSA originated from backbone area but allow type 7 originated from within the NSSA (nonbackbone area ASBR).
Totally Stub = Totally (block3LSA) + Stub (block 4&5 LSA)
Totally NSSA = Totally (block 3LSA) + NSSA (block 4&5 LSA but allow type 7) + Stub (block4&5 LSA)


"Totally" means Block 3 LSA (Cisco proprietary configured only on ABR) in addition to whatever LSA's are being blocked by the word following "Totally".
e.g. Totally stub: Block 3 LSA in addition to the ones already blocked by the word "Stub" which are 4 &5


"Totally" Is not on itself an area type.

[awsal-bayati]

most amazing fast explanation i ever seen, thanks jeremy, you are my cisco learning godfather, i achieved CCNA certificate because of your nuggets and also almost achieved the CCNP route exam 742/790, , , , retaking the exam in 3 days with gods