So far in this series I’ve covered Type 1, 2 and 3 LSAs. Next I’m going to cover Type 4 and Type 5 LSAs with the help of this topology. Before we get started though, let’s have a quick refresher on what these LSAs are used for: Type 4 – ASBR-Summary LSA – this is needed because Type 5 External LSAs are flooded to all areas and the detaile...
Up until this point I have only covered Type 1 and Type 2 LSAs in this series. I’m guessing by now you must be quite familiar with them and are interested to hear about the other LSAs, so let’s move onto Type 3’s. This is what Wikipeda has to say about Type 3 LSAs: Type 3 – Summary LSA – an Area Border Router (ABR) takes information it has ...
In Part 3 I demonstrated how you can use Type 1 and Type 2 LSAs to map the topology an OSPF area. In this post we’ll do the reverse. By looking at a network diagram below, you should be able to determine the following: Who will be sending Type 1 LSAs? How many Type 1 LSA entries will there be? What will the “Link Count” be for each of th...
As mentioned a couple of times in this series, Type 1 LSAs differ between Broadcast and Point-to-Point segments. To demonstrate this, I’ll be using the same topology as before. The only difference is that each interface has had the “ip ospf network point-to-point” command applied to it. You may recall that the reason why I’m talking only abou...
In my previous post I covered Type 1 and Type 2 LSAs in relation to broadcast networks. In this post I’ll demonstrate how you can use these LSAs to map the topology an OSPF area. Broadcast Networks - Type 1 + Type 2 LSAs = Area Diagram First, let’s take a look at which LSAs exist in this area: R1(config-if)#do sh ip ospf database ...