Can I rebuild an OSPF topology using ONLY the LSDB?

OSPF Routers share LSA to synchronize their LSDB, then they use their LSDB to rebuild a topology map of every router and network.... but is the LSDB really enough to rebuild the entire topology? In this video, we put that to the test.

Jeremy, of Jeremy's IT Lab, has created an OSPF topology that I have never seen. And I'm going to try to draw out the entire topology, just like a Router would, using ONLY the contents of the Link State Database and the details of each LSA.

This video is an addendum to my Practical OSPF series, which is a modern, practical look at the OSPF protocol.

Practical OSPF - Full Series:
   • Practical OSPF  

===== Pre-requisite Videos =====

OSPF Areas, What they are, and Why they exist:
   • OSPF Areas and OSPF Types of Routers ...  

LSAs - Type 1 / 2 / 3 / 4 / 5 - a practical look at Link State Advertisements:
   • OSPF LSA - the BEST explanation of th...  

Type 1 and Type 2 LSA Deep Dive
   • OSPF Type 1 LSAs and Type 2 LSAs // L...  

Type 3 LSA Deep Dive
   • OSPF Type 3 LSAs // LSA Deep Dive // ...  

Type 4 and Type 5 LSA Deep Dive
   • OSPF Type 4 LSAs and Type 5 LSAs // L...  

===== Timestamps =====

00:00 - Teaser
00:09 - Challenge Introduction
01:00 - Rules and Setup
02:01 - Each Router sends one Type 1 LSA
03:19 - Looking inside Router 1's Type 1 LSA
06:11 - Looking inside Router 2's Type 1 LSA
07:00 - Transit Networks point to a Type 2 LSA
07:52 - Looking inside a Type 2 LSA
09:34 - show ip ospf database router (Type 1 LSA)
11:15 - Looking inside Router 5's Type 1 LSA
14:20 - Looking inside Router 3's Type 1 LSA
17:02 - Looking inside Router 4's Type 1 LSA
19:40 - Looking inside Router 7's Type 1 LSA
21:00 - Type 5 LSAs mean Redistrubition
21:44 - Looking inside the ASBR's Type 1 LSA
23:32 - Looking inside Type 5 LSAs
25:52 - Let's see how I did
27:48 - Single Area OSPF vs Multi Area OSPF
28:44 - Outro



===== Commands used in this video =====

show ip ospf database
show ip ospf database router
show ip ospf database network
show ip ospf database external

===== Music =====
Event by 2TECH-AUDIO | https://2tech-audio.bandcamp.com
Music promoted by https://www.free-stock-music.com

===== Jeremy's IT Lab =====

Jeremys' IT Lab Youtube Channel:
   / jeremysitlab  

Full CCNA Course:
   • Free CCNA 200-301 | Complete Course 2024  

Full CCNP Course (work in progress):
   • CCNP ENCOR v1.1 350-401 | Complete Co...