Okay, so I brought up the console for r1. And so first thing as I said we have to establish an introduced interior routing protocol in r1. And we'll continue from there. So follow my step and I hopefully you can understand this BGP configuration method. So let's do that. So called D router OSPF one network.

So we will run the OSPF net on the on the main links between the routers. So the first thing is 192 dot 168 dot 12 dot one And now we will also enable BGP router. And we set the autonomous system that our one we'll be using is the 65511. So 65511 Okay. If it was a real router one, let me type it actually. So auto summary, no auto summary.

And then I'm going to also advertise the loopback address in BGP. So the neighboring device is the interface IP address of our two and that is 192 dot 168 dot 12. Two and remote as. And we will be using the autonomous system here are two. Now there's two more lines for BGP configuration. So one is BGP configuration identifier.

Hundred. And the other one is BGP peer. So BGP, peer peer GP configuration peer okay peers and our peer is basically our once our choose autonomous system and I believe that's all we need to do in r1 and we will move on to our to show IP interface brief. Let's just keep that because we need that information when we are bringing our two Okay, so I have the console here for our two and as you know our two is neighboring two routers, one is r1. The other one is hard three well as well as its neighboring our five but Okay, so first is basically OSPF, we'll introduce OSPF so router, OSPF one and then the network which is the network link between our two and r one and r two and r three. That's what we will be enabling OSPF in.

So one is 12. Two and the open network is now I created a course on OSPF I will recommend that if you want to learn about OSPF How to establish OSPF are neighboring and please go into my course it's the practical implementation of OSPF. It's, it's a great course. I tried my best to cover CCIE level detail details in OSPF. I can always I can also see that there's a neighboring adjacency that's established between r one and r two. So, router BGP.

Now we said our two would be using the autonomous system of 65512. No auto summary And the network that I will be advertise advertising is the loopback address. And the neighbor is 192 dot 168 dot 12 dot one and remote 65511 I believe. And the other neighbor is the neighbor in art three is the neighbor r three and r three I believe we are using the interface which is 192 dot 168 dot 13 dot one and remote as 65513 Now the question is why I'm using 655 11 12 655 13 that's because as I introduced you about PGP, those are private autonomous system. And those can be basically given to private organizations to use and it's on. It's on a subscription basis.

So the other command I'll do is BGP configuration. Identify 100 and BGP configuration peers. Now we're here have to basically put The piers which is the as number four r one and r three, so it's 65511 and 65513. Okay, exit and save that. Okay, we will be moving to our three let me bring up our three console. So this is our three console here and we will do the same steps which is basically enabling OSPF first.

So router, OSPF one and there are two network links here in router three, network 192 dot 168 dot Okay, dot 13 dot one, area zero okay yep, I see there's a adjacency there. And the other network is 192 168 dot 40 320. And now let's enable router BGP. Now the autonomous system we'll be using for r 365513 and no auto summary and the Navy versus our two neighbors here. Neighbor one is basically our two. So we need to know the next hop interface IP of.

So it's 192 168 dot 13 dot two remote as 65512. So that's the information about our two we are entering here. And then again neighbor 192 dot 168 dot 43 dot one. That's the next hop IP address to our three which is basically pointing towards our four and we are saying remote. As I can hear the neighbor missing ah here remote as 65514 so we did that. Did we actually advertise the loopback interface?

Okay, let's add that Now let's do the BGP configuration, BGP configuration identifier. Hundred and BGP configuration peers. The two piers that we have is basically 655112 I think one, two, and 6551465522. Okay, so we finished the configuration in our three. The reason why we are getting all these messages and notifications about our force. Neighboring status is because it's still we have not configured our floor yet.

So it's a little bit of a pain to configure our for when we ask So many alert messages from the from the console interface. But we will try to do it quickly. And it's not a, it's not a big issue. So let me bring up our force console and go through the configuration. Okay, so our force configuration is basically pretty, pretty easy. It's the same thing.

So first thing we will introduce is county router, OSPF one and the network. The first interface link of the network is 192 dot 168 dot 43 dot one zero dot zero dot zero area here is zero. So that's not work. And we will actually now Enable BGP, BGP router BGP and autonomous system is 655 I believe we said it's going to be using 65511065514. Okay, so no BGP router. So I wonder why it is giving me show.

Okay, so because our four was basically part of the older part of the previous configuration from the previous lesson Let me just raise that and come. Okay, so basically what I did is I removed the old configuration from this router. I don't know why it kept it all along. And that was the reason why we were getting a lot of the messages. So that it's clear now and now we understand why those messages were coming up. At the same time the peering was trying to happen between r three and r four.

But now that this is clear, I think it's much better. So let's introduce router BGP 65514 Okay. And we will be enabling the network link between. So the network is the loopback address that we will be enabling First, no auto summary. Okay, so we did that part and the other thing that we need to do is so OSPF is already enabled, I believe right now we already worked on that. So now we will establish the neighbor relationship which is going to be 192 dot 168 dot 43 dot two remote as 65513.

So that's done. And the other thing we need to do is BGP configuration. Right? identifier, we have to add that and BGP configuration Here's 65513 I believe that's all we need to do. And as I can, as you can see adjacency is established for the BGP, so that's done. Let's save it.

Okay, so that's, that's all about our four. We will move on to our five I believe our five is already configured from before in our previous lab, so if I do show run config Okay, so it did not save those configuration. So, no problem let's let's add the configuration file. Five Let's enable BGP first in our five. I just want to make sure we're touching the right interfaces here. So show IP interface brief.

We have that already. So router BGP 200, no auto summary. And the network is five dot zero dot zero dot zero. And the neighboring device we said it's going to be I believe what we said it's going to be the interface. So the neighbor is to five dot one dot one dot one and remote as hundred Okay, so our neighboring device for our five is always going to show as 100. Okay, so that's why we have to put as 525 dot one dot one dot one, if you remember from our previous lecture, that's the IP address of this interface here, which is F 00.

And that's all we needed to do. Now from the The one thing I need to do in r two is really to make the F Zero slash zero interface passive right. So and the way you do that is if you go to column T and you do router OSPF one, right, and you have to say passive interface, fa, zero slash zero That's all we need to do in order to. And the reason we what we are doing that is because you don't want the routing information from 100 to be advertised to our five and that's why we have to put this interface as passive. Okay, so from our fives perspective so basically let's bring up our five we are we already have here our five. So from our five perspective, what we will see is this show IP BGP.

Begin network. I don't know why sometimes it works. Sometimes it doesn't work on the simulation. So okay. So we do see that the IP BGP is good. advertised to is actually looking at five network and it's getting advertised.

Okay in the routing domain and from so in order to basically what we will do is there's one more thing we need to do in our two which is if we go to the router BGP 65512 we should stablish also a neighboring relationship with our five which I don't think we did that so two five dot one dot one dot one dot two remote AAS and our five is in the s 200 so and yes, I do see there's a, there's a neighboring adjacency established between our five and our two. So that's great. So if I go back to our five and I do that dot zero dot zero dot zero is from r1 to dot zero dot zero dot zero is from r two, and so on. The Asterix sign means that it's a valid entry and the greater sign here means that it's the best entry for this prefix and the next hop is 25 dot one dot one dot one, which is basically our tos interface, right?

So that's good. That we can see that. Now if we do the same thing, and we bring our one and we just put show IP BGP and we say begin network. Now here the output for r1 we can see that there is a network which is five dot zero dot 00. So, it is getting the information from our five which is great and the other networks that it sees is internal. So those are coming from basically autonomous system hundred.

And the path is here which is basically for this network autonomous system path that this network is coming from is six by 512. This network is coming from six by 51113 and then 65512 and four network which is four dot zero dot zero which is Elvis. We are five we See that the path is follow through. And that's why this is a path vector protocol. And it shows that it's internal internal internal. And the last one is showing that it's getting learned from 565512.

It is internal because it seizes internal r1 C's is as internally advertised. But it's also giving me the autonomous system 200, which is basically our five autonomous system. So this is the result of this lab. The A s path, basically in the parentheses are the private AAS numbers. That's what it's, that was, that's what it shows. Which is great.

The other thing is, if it's not in parenthesis here that that is basically it's not part of the configuration. So parenthesis It's a configuration configuration. So, this is not part of the configuration 200 is not. So I hope in the end of this lecture, I have clarified how to apply BGP configuration and, and I'm pleased if you can do a similar lap on your own, that would be great.