Areas and LSAs

- [Instructor] All right, so OSPF is often compromised…of multiple areas.…Let's take a look at what these areas do…and why they are important.…Now, here we can see multiple areas of an OSPF topology.…On the left we have area one…and on the right we have area two.…In the center we see the backbone area or area zero.…Now, let's just break this down, right?…This particular topology needs to be dissected for us.…First thing I would like you to know is…by breaking up an OSPF topology,…that's how OSPF gets its scalability.…

We can go to large sizes…because we're creating communication limitations, okay.…We're not shooting our hellos…all the way across the topology here…from area one to area two.…That's just not how it works.…So, we are able to save on communication…by limiting to only those required routers,…so whoever needs to know, that's who we're going to update…and we'll talk more about this later,…but this is how we get the scalability.…We also create areas where we can summarize routes.…

So, here you see that the router straddling the line there…