OSPF LSA - the BEST explanation of the Types of OSPF LSAs

OSPF Routers share routing information using Link State Advertisements, or LSAs. There are 5 main types of OSPF LSAs, and all of them are used to populate a Router's the Link State Database (LSDB).

In this video, we illustrate and explain the 5 main types of OSPF LSAs:

Type 1 LSAs - Router LSA
Type 2 LSAs - Network LSA
Type 3 LSAs - Summary LSA
Type 4 LSAs - ASBR Summary LSA
Type 5 LSAs - External LSAs

This is lesson 9 of the Practical OSPF series. The full series is available here:

00:00 - Lesson 9, 10, 11, and 12 - OSPF LSAs Types
00:50 - Topology Introduction
01:15 - Type 1 LSAs - Router LSA
02:00 - Type 2 LSAs - Network LSA
02:26 - Simple Illustration of Type 1 and Type 2 LSAs
05:19 - Type 3 LSAs - Summary LSA
08:41 - INTRA Area Routes vs INTER Area Routes vs External Routes
09:36 - Type 5 LSAs - External LSA
11:11 - Type 4 LSAs - ASBR-Summary LSA
13:29 - Summary / Outro / Next Lesson

=== PRE-REQUISITES ===

LSAs and LSDBs:

OSPF Areas and OSPF Types of Routers:

Designated Routers and Backup Designated Routers (DR / BDR):

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[PracticalNetworking]

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[scottspa]

Ed, you're a bit of a savant. I will never understand how you can have such a grasp of all of this. Your instruction is fantastic, I will have to review this when I'm not half asleep, but what you share with us is AMAZING.

[aler]

Best explanation I have come across so far! Thanks for the great work.

[Arvindkumar-vsmo]

Watching OSPF topics on your channel. One of the Best teacher. You are awesome in conveying the information with pictorial form.

[kingafadll]

I want to say thank you, I am bluffed by how you have explained that, I have purchased many of CCNA & CCNP courses, but no one has explained it the way you did.
Thank you

[idowuaina]

Your videos are simply the best I have come across. Rich in content and details

[Just-Browsing-]

The diagram you made to help explain this is excellent!

[rickwiers]

This is the best video I have seen about LSA's in a simple understandable way!

[lokeshreddysura]

I have been searching for almost 7 years to know what is the LSA Types differences and their nonsense theory and you nailed it in a shot.

Superb.

It feels like no instructor knows what exactly LSA's are except you.

[tonicshahov]

Your explanation of LSA types is trully best, as you promised in description!

[dclife_]

WOW. Best content I've run across. Greatly appreciate your style.

[GokhanDoymaz-oilx]

Perfect explained LSA Types 1, 2, 3, 4, 5

[TheKhidki]

Saying Thank you is a very least. I really have cleared many doubts through your content.

[usmanhamid]

All of your videos are presented with such a great explanation and animation that it makes confusing concepts very clear, very quickly. Thanks!

[anilkainikara]

Amazing content. The slide designs are appealing to the eyes. And your exploitation is good.

[uzar]

Sorry to be that person but there are actually 11 types of LSAs (OSPF).


LSA Type 1 Router LSA
LSA Type 2 Network LSA
LSA Type 3 or 4 Summary LSA & ASBR LSA
LSA Type 5 Autonomous System External LSA
LSA Type 6 Multicast OSPF LSA Type
LSA Type 7 Defined for Not-So-Stubby-Areas
LSA Type 8 External Attribute LSA for BGP
LSA Type 9, 10, 11 Opaque LSA

RFC 5250 back in 2008 discusses these. Cisco, one, it not the largest, vendor which many people are familiar with, only supported 1-5 for the longest but other vendors supported OSPF LSAs (6-11) well before especially with the advent of Traffic Engineering (10-11 "Opaque" LSAs). Very good explanation on the 5 types you discussed here.

[chantellemorehead]

A passed my CCNA yesterday!! Thank you for the videos, they really helped

[samueltetteh]

Great presentation. You simplified every thing .thanks

[DarkArchery]

Thank you very much.
I really appreciate your explanation with moving diagrams.

I currently prepare myself for an exam and it was really hard for me to imagine how it works just out of the slides.
Before this video I didn't even understand where the LSA are all send to.

[mikemoman]

Brilliant. You explain these topics so well. Thank you.