Hello there, this is your host visa career and in this course I will be talking and showing you how to implement OSPF in different forms. We will touch base on all the details of OSPF and by showing different scenarios and building different topologies and applying OSPF. But before we do that, let's start with some important facts about OSPF. OSPF is is an open standard interior gateway routing protocol. And part of that there are two versions which is always pf version two which is used for ipv4 and OSPF version three that's used for both ipv4 as well as ipv6. It's a link state protocol, which means that updates are incremental and in their event driven.

It guarantees loop free topology, which is a great feature. it's scalable for large networks to areas. As we go along in this course, you will learn how to implement that. It does not use hop count to calculate the best path it uses a bandwidth based cost metric. It is it also uses security if you apply and that could be a clear text mt five as a che or IPsec. Now OSPF discovers its neighbors by sending Hello packets Hello packets are exchanged every 10 seconds that intervals are set to 40 seconds.

We will go through that during some of our labs. OSPF version two uses a multicast to send hellos. And those IPS are there two to 400 to five or two to four dot zero dot zero dot six. It cannot be send unicast packets and OSPF version three uses multicast as well. I've had 02 colon five or ff 02, colon six or even unicast. OSPF has has its own transport protocol, which is 89.

It's good. It's good to remember that AIG RP is 88 OSPF uses 89 Some of the other things is how does it work? How does OSPF work? SPF discovers basically OSPF neighbors and exchanges topology information it chooses the best path by computing the shortest path first. And then in the end it it maintains the neighbor and the topology tables all across the the network all across the network all the routers have to agree on the topology to create guarantee a loop free topology. It is scalable for large environments as you know, through areas which is a good thing it has very fast convergence as we integrate It's a link state protocol.

It's very efficient, reliable because of the multicast and unicast updates. So that's all about the facts of OSPF. The important ones are the ones that are listed here. And let's go ahead to it with our first lab which is basically OSPF Point to Point networks and the topologies in front of you will go through that and we will we will apply OSPF and we will see how it's done. Thank you.