Hello there This is your host leaves Korea and we will start to the OSPF scenarios by introducing OSPF in point to point networks first. In this topology basically we are going to configure the three routers in. In an OSPF environment ages zero, we will advertise the loopback interfaces 40s routers will provide router IDs to the routers, and we will make sure that the network types are point to point we'll go through it step by step and build this network and see how things roll. Since this is the first topology, I am sure that we will grow into a much bigger topologies and touch base into a lot more different scenarios. So let's start So first of all with r1, what we will do is we will r1 will be considered our dc dc means that it's a data communication equipment. And it controls the clock rate on the serial interfaces so so that's how the interfaces work.

Actually one, one end is DC and the other end is dt. dt is again, it's data communication equipment terminal. Okay. So, so let's start so coming up starting all the routers Okay, so r1 came up. Let's go into the configuration mode one to five times. Okay, so Sit down interface network IP address there now we have to configure clock rates as well.

Loopback interface okay we don't have to do no shut it it's our part automatically know We have another interface as well which is interface is zero slash zero IP address on top 1255 to zero. So first we will configure the connectivity, the interfaces for each of the routers and then we will start with the OSPF doing the same thing or two interface to zero no sharp. Let's go to our three. Okay, we'll configure our three the same way. So going to configure all the interfaces here. interface, zero slash zero 22552552552 interface loopback loopback zero tivities to 500 it's brief.

So let's see if we can ping the neighboring router which is our once interface, our once f 00 interface yes we can create conflict We're back in our one show IP interface brief just to make sure we have the serial interface IP address the 00 IP address and all of them are up. Now we're going to move on to the to the actual lab where we have to apply OSPF area zero and give her a router ID. So let's start. So come and say router OSPF one with a router ID of one dot one dot one. Now router IDs are not really important, but it helps identify The neighboring devices and you will see that when we go along and verify the status of the neighboring devices, you will see where the router ID is going to show. If router ID is not given it takes a loopback address.

But it's a best practice to apply router IDs to no network zero that's a loopback network. That's the serial interface zero and those are the two networks. Now one more thing we have to do is on the loopback addresses we have to specify the network type is point to point so interface zero and IP OSPF network, point to point you may have to do that in all the interfaces that are participating in the world. appear as a verification all of them has to be point to point. So this router is ready. Now we will move on to our two backing charts, show IP interface brief make sure we have the interfaces that we configured and we can start with our to config.

And we're going to say router OSPF one that one is the process ID. And it's important to give it a process it was gonna give it a router ID as well. Sorry man We can apply it to network which is area the network is 2021 more thing I need to here is on the loopback interfaces we have to specify IP OSPF network point to point. As you can see here it says that there is an MPR request So it has found adjacency with the router ID of one dot one dot one dot one, which is good news. Now we move on to our three. We are in our trade show IP interface brief.

Let's make sure we can see the interfaces. Now let's do the same thing. One router five zero now as you can see, I mean there is an adjacency with the router one and router ID of the router one is one don't want so great. So we have done the configuration now what we need to do is make sure that we can see the IP route tables and the topology and make sure that that the network is fully converged. Now, we will start today verification process, verifying the configuration. So let's do that.

The first command we will apply is to check the IP route table. Show IP route who was here. As you can see r1 is seeing two neighboring devices. One is two networks here when one is 220 dot zero dot zero dot zero dot zero and the other one is 30 dot zero dot zero dot zero dot zero. As you can see, those are the two loopback addresses that we provided and our two are not three and those are the interfaces that are coming up which is good. Now let's check our two as well.

Show IP OSPF show IP route course here. As you can see it can see all the advertised networks from the other routers here as well. Now let's go to our three here. And indeed We can see all the Alta network from other routers topology. One thing we need to verify here as well is let's see who's the neighboring device. Okay, we know from our topology, the neighboring devices are one.

But let's check show IP OSPF. neighbor and we can see one dot one dot one dot one is the router idea for one and it's fully converged and it says Dr. So Dr means is the designated router. But I am sure that in this type of networks, which is point to point network and in this topology specifically, we don't want to have any, any D or elections happening within the topology, so we will change that and we'll see the results. Okay. So the way to change it is by going into the interface F Zero slash zero and changing the network type of the face to face Cirrus slash zero IP, OSPF network point to point as you can see generated another full loading process of the topology.

Topology exit. Let's compare that now show IP neighbor as you can see now it changed there is no dr designated here. The other thing we could verify is we could do the same thing as well on the other routers. We could basically check the hello and that intervals of the interfaces. So show IP or fear interface FA zero slash zero. And we can indeed verify the Hello packets or 10.

The Dead End intervals are set to 40. And the network type is point to point. So I think we achieved our purpose here in this lab. We went and we checked the interfaces and the type of the interfaces as well as how to change your SPF. Then network type from from broadcast to point to point. I hope this was useful.

And we can move on to the next topology as we go along, so stay tuned. Thank you very much.