Hi again, this is your host Habib career and in our previous lab, we have discussed the sparse dense mode. And we did a lab on sparse dense mode, as you know, sparse dense mode is is interesting technology but at the same time, it's it's it's not as scalable as we discussed and we have seen how the flooding happens on the porch just for the receiver to start accepting a stream, the reporting and the query goes into every port. As an alternative, most of the organizations have started implementing sparse mode. And this topology in front of you is the one of the most famous topologies and one of the most practical topologies in small to medium organizations and I'm glad I have to bring it up in this course. Now, one thing you have to note that this topology configuration for the four sites is done in using dmvpn.

If you are interested to learn about dmvpn and phases of dmvpn I have a course that is published on how to configure dmvpn and secure the dmvpn sites. So, you can basically go through that and and learn about dmvpn beside that I mean this this lab is not related to dmvpn but the connectivity between r one r two r three and r four is done through dmvpn So, I will show you the company Integration is that's not a issue, but we will need to really understand dmvpn properly and to do such a lab in an in an in a in a bigger scale, or in a practical sense in an organization where you would like to bring up sites. So let me bring up r1 first and let me come to the console here for our one. This is our ones console. As you can see, I have type show dmvpn.

And I can see three sites are connected here to nh RP, which is a dmvpn protocol. The other thing that we want to do here is basically, in this lab it says that configure, implement and verify payments, sparse mode, operation and adjacencies So if we look at the show IP interface brief, if we look at the interfaces here we have basically on each of the routers we have three interfaces. One is the Fast Ethernet zero slash zero which has the IP address 172 dot 16 dot one dot one for r1. That's the N BMA IP address. Usually this IP address is provided by the ISP and once they give you an IP scope for your WLAN connection, you will have similar range of IP scope and you can configure the interfaces facing the internet or SD when in this case, to have those IPS right and, and the other.

The other interfaces the loopback zero, we are assuming that there's a network Behind the router that is basically getting simulated as loopback zero and then the tunnel one interface which is the basically the tunnel that is created to stablished dmvpn VPN okay. So one thing so this is the this is the router, but one thing we have to do for multicast IP multicast routing is to have full convergence for all the networks to for the other side so what we will do first in this case is we will we will configure the router OSPF area zero. So, let's do that oh SPF one network. So basically we are assuming that we are at tising the network loopback zero to all other routers as well at zero and part of that is also to establish a full convergence for all the tunnel interfaces Okay, so that's good.

So let me bring up the I'll bring up the console for our, our two as well, an r two and r three and r four. Okay, so I brought up the consoles for r two r three and r four. So what we will do first is we added the router OSPF configuration in r1 and we are going to do that Same thing in our two, but in our two first of all we have to look at the interfaces. So to show IP interface brief here and as you can see I have three interfaces as I mentioned. So come to the router OSPF one and what we want to advertise as loopback zero antenna one. So network 2020 dot 20 zero as you can see it has stablished it has established neighbor relationship here we will do the same thing with our three as well.

So, show IP interface brief and I'll call route OSPF on network can see the activities of having adjacency I could see that the adjacency is going down here. This is part of my troubleshooting that I will do now on the tunnel interface. Okay, so don't worry about that. So let me go and now bring up the interfaces in our four So, this is completed we have applied the the router OSPF configuration here. Now, one thing that I have to do is to really check the the tunnel configuration on all the on all the routers. So one thing is because our one is acting as our hub and the Rest of the routers are acting as spoke so.

So one thing that I have to do is go to interface interface tunnel one I know it's very difficult to put this together IP OSPF network point to multipoint. This is important. And also there's another command that I need to put in here which is IP OSPF, Hello internet interval 10, IP OSPF Hello interval 10. Things have stabilized here. Let me save that. Now let me go back Hear and do the same thing on the tunnel interface interface tunnel one, IP OSPF Hello interval 10.

Now as you know the one of the golden rules is that if you don't have full convergence in your network, IP multicast will not work because it's a sub layer technology that runs on the benefits from the IGP routing table. So, now that is done, the first thing that we need to do now is basically make sure that if I do show IP OSPF neighbor, I can see the neighbor. So are two can see the neighbor routing protocol for r one and if I do same thing in r four if I do show IP OSPF as you can see, I can see the neighbor which is r1 everywhere from all the other routers Okay, so now we are moving into into the configuration of the IP multicast. So first thing first in r1 what we are doing is we are adding the IP multicast routing, right actually we have to add IP multicast routing to all the routers so let's do that so config t IP multicast routing same thing here my And as you know when you add IP multicast routing, this will provide you with the show IP route and route table Believe it or not, this is a lab for a CCIE course that and it actually came in one of the exams for the, for one of the gentlemen I know and that's the reason I put in in this course so, so you are aware of this type of topology could come in in the future if you're going for your exam.

And this topology is also beneficial if you are dealing with IP multicast type network for different branches and sites. So this is So, as I said, I mean what we are doing now here is each router we will have to add the IP Pim sparse mode to the interfaces that we want to join to multicast. So, basically in r1 if I go to interface zero loopback zero out IP Pim sparse mode and the other interface that we will we will add is the tunnel p Pim sparse mode. So similarly in each of the routers will do the same thing, interface, zero and then interface tunnel One same thing here not three as you can see things are getting activated here neighboring relationship is getting stablished interface. There you go. Similarly if I do here in our four So this is completed, I mean, let me I like to save the configuration.

This is a great habit to keep, so you don't lose the configuration. So now that we have configured IP Pim sparse mode in all the interfaces that we want to keep, we want to have a part of the multicast routing. What we can do now since r1 is our hub, what we can do is we can look for the neighboring devices on r1. That part of the pimp so if I do a show IP Pim neighbor as you can see, I can see all the neighbors that have Pim sparse mode enabled. As you can see, there's four. There's three, there's two, these are the, the tunnel interfaces of the routers showing as showing as Pim sparse mode and they are actually neighboring the r1 router, which is perfect.

That's what does the intention and we have achieved our intention. So basically, what we did right now is we completed part, task one, task one. Task one mentions here that implemented verify Pim, SM operation and adjacencies and this is what we completed. Now, we will move on to task number two Task number two says that implemented verify the use of static random point r one should be the rendezvous point for a private group and r three should be the RP for the remaining group. So here basically what we will do is we will apply an access list on all the routers based on the condition that is provided here. So, let's do that.

So, in r1 and what we will do is we will apply an access list so we'll say county access list one permit. So, private group is 239 dot zero dot zero dot zero and then zero dot 2552552 255 and basically, I p m r p address 10 dot 10 dot 10 dot 10. One is the access list number, IP Pim, RP address 30 doctor the doctor the doctor 30. So basically this is the command to choose rendezvous point and make a random point address basically electing a rendezvous point statically for any of the interfaces that you would like to have random point, so here we have chosen 10 dot 10 dot 10 dot 10 for a private group 239 dot zero dot zero dot zero network And we have chosen another random point which is basically the interface, which is the loopback interface of our three which is 3232 3230.

Now we can apply the same configuration on all the routers and that's how you should do it you should configure the same access list in all the routers for for this type of topology. Because you are telling every router that for your RP point is going to be those interfaces so access list one or mad We completed the configuration in r two we are moving on to r three. And that's the reason why I brought up all the consoles in one screen. So I can basically do it all together and also give you the maximum attention here in all and you can see the basically the actions that are happening on each of the routers as I enter the commands Moving on to our flow Now similarly we'll start adding the access list. Okay, so let me save the configuration Okay, so this is completed. One of the most important commands that you should remember is RP mapping.

So if I do show IP Pim, RP mapping, as you can see, it will tell me which which, which, which interfaces are basically the rendezvous point. And which groups are part of the other random viewpoints. So, you can see by default two to four dot zero dot zero dot zero is basically a rendezvous point has a rendezvous point of 30 dot 3030 to 30. And this is basically the group to RP mapping tables that you will get. Similarly if I do the same command here in our for show show, IP Pim RP mapping. I'll get the same in all the routers just to confirm.

There you go. So we got the same for on all the routers. So let's say for example, our four is interested in joining an igmp group of two to four dot five dot five dot five, which Basically, so, for for our for the rendezvous point will be our threes interface which is 30 3030 dot 30 right. So, let me let me do that. So, if I do interface loopback zero and I will say ip igmp join join group 2245 or final five this part is our testing here So, what I will do now is I will basically type show IP route and it will tell me all the all the groups that are available On r1 and with what are the rendezvous points. So the first group that you notice is 2245255.

And that's the group that we asked our for to join. So let me ping it, ping 224 dot five dot five dot five. This is part of our testing. And there is a reply coming from 10 100 104. You can see that and if I do show IP route Yes, it's showing me that it's, it's basically the ping went from r1, which is 10 dot 10 dot 10 dot 10. And that's The source and the associated group is 2245555.

And that's why we got the response back. Now in this table you can see the reverse path forwarding. That's the reverse path forwarding for loopback zero. Usually in the IP packets usually the receiver waits until the end of the sender or the server sends the packet to the receiver, but here the receiver is requesting the packet and and the source is providing the packets or the reverse path. Communication here. So this is what I wanted to show in this lab.

I hope it was easy and you have understood it. It's very simple. Basically what we did is we we created two static RPS, one RP for the product. Group 239 dot zero dot zero dot zero. And we made that to be we made RP in r1. And we created another group which is the two to four dot 50505.

And we made our three to be the RP for that group. And basically we asked our for to join a group and once they joined two to four dot five dot five dot five, our three became the RP point for that group. As you can see here, it became DRP point for that group. And once you start pinging or you're interested to send a stream to the group to two for the Father, Father five from any of the interfaces in the routers, you will get a response back And this was the intention, you will get a response back. So, that is the intention. It's, it is clear.

So, basically another point of discussion here is when every Pim is enabled on the router it will always create to to four to five to 505 in the M route table. This is created as the join message are sent to the RP for that group, right so, it's simple as that, I hope you can practice this lab in your own and in your own viral simulation or TNS simulation and and and try to do it. This will give you more experience. Thank you very much and I'll see you in my next lap.