This page has been created to gather suggestions and feedback regarding our OSPF course for CCNA candidates. It is intentionally made public so that everyone can read and participate. Everything must be transparent for us all.

This is the final configuration lab, designed to check whether you have understood all the OSPF concepts we have seen in the course. If you successfully complete all configuration tasks, you are more than ready to pass the OSPF portion of the CCNA exam.

When an autonomous system border router (ASBR) redistributes an external route into the OSPF domain, it creates and floods a Type 5 LSA into the area it connects to. The LSA is forwarded unchanged by area border routers and reaches all routers in normal OSPF areas. 

The Open Shortest Path First (OSPF) routing protocol supports four different authentication types:

Nowadays, security is a top priority of every large organization. In that context, OSPF authentication provides several security benefits, particularly in environments where network integrity and data confidentiality are essential. 

The OSPF protocol uses a very CPU-intensive algorithm called the SPF. It performs a number of calculations depending on the size of the link-state database (the LSDB). For given N LSAs in the LSDB, the algorithm performs computations proportional to N*logN.

In the previous lesson, we learned what OSPF Multi-Area is and the terminology related to the multi-area design. 

This lesson goes further and explains how external routing protocol is redistributed into the OSPF domain and what are the roles of LSAs Type 4 and 5.

Open Shortest Path First is a very scalable routing protocol. Its design supports scalability by using a concept called OSPF Area.