This is what this is Dmvpn.
Phase one.
But before we go to phase one, before we go to the MVP and phase one, we still have to understand
what an M is.
What is a multi point?
Do you remember yesterday we talked about tunnels.
We talked about how tunnels were scalable.
Much more than crypto maps.
Right.
If you compare that to a multi point guy, there is a huge difference.
What do I mean by that?
N is different than a normal guy in a sense that in the guy that we did yesterday, even though we still
have that confusion of the header size, which is not an issue because you're still reducing overhead
in the guy that we did had a router here, which was R1, it had one tunnel with R2 and I had to create
a separate tunnel.
Without the different addresses.
So this was 168.1.1.
This was .2.1 or 2.0 slash 24 slash 24.
So as many number of peers, you have as many number of tunnels you would require with different addresses.
Same is the concept here.
Now, R2 and R3 wants to communicate to each other.
They could have done it through R1, but that would be too much load on R1.
So what they would do is they would create another tunnel between themselves.
Certain from R1 to R2.
A tunnel from R1 to R3, then R3 to R2, a separate budget.
Solve the issue of scalability.
It does to some extent.
But now imagine scalability means what?
The more the devices come in, the more scalable means, the more easier it gets.
But now imagine if I have R4 coming into the same picture.
R4 would require one tunnel for full communication, one with him, one with him, one with him three.
Right.
R1 has another one now.
Another guy comes in.
R5 more tunnels.
One, two, three, four, five, six comes in.
He would require five.
R7 comes in, he would require seven.
Sorry.
Five, six, seven, eight, nine.
Like that.
Each guy would require the total number of him.
For example, R6 less than one and minus one is five times.
Each guy.
Five tons.
So our five is connected like that.
Our one will be also connected like that.
Our four will be connected like that.
Our two will be connected by itself.
So by complicated the situation can get tricky.
The more you expand, the more difficult it becomes.
Yes.
For three four sites.
Okay.
What about you have 200 sites.
How do you manage those with these tunnels with having different IP addresses for every different connection
that you have?
Right.
So it is scalable only to some extent.
We want to increase that scalability to up to at least 2000 spokes.
Right.
How?
Jerry came up with a new concept which was known as multipoint zero.
When you look at a tunnel now, you don't look at a tunnel from a point to point perspective.
Now you look at it from this perspective.
One, two, three, four, five.
They?
Similarly.
Similarly, yes, if you want to look at it from from the surface, that's how it looks like.
But we'll go deeply into the details of how it works.
From the surface, it looks like a switch.
So 192 168 1.0 slash 24 will be your main tunnel.
Then your end points will be .1.2.3.4..
This will be our main aim to create something like this.
A tunnel which looks like this looks weird, doesn't it?
We know how source and destination works.
How is this going to work out?
As this whole concept we're going to work on.
We'll see before that, just keep this in mind.
Let's configure this.
Now, the best way to configure topology like this is also the easiest way.
Interface zero zero IP address is one five.
16:00.
You need it out.
Bit out.
Winning gold 66, which is the Internet, also would require a loopback to the IP address of ten 111.
Because that is the whole point.
Eventually, I don't want the hubs, all these devices to talk to each other.
I want networks behind them to talk to each other.
Right.
Starting from hour one.
Then I too.
Similar config.
26.2.
Next stop is 26.6.
Loopback is.
Conduct.
13333.
And
I thought.
We are is open for any mistake that I might make.
Finally R6.
R6 I'm going to configure separately.
I need to see the interface.
0001 50 .1.6.6.
Zero 130 6.6.
Zero three.
46.
Finally.
Let's set from R2 generated 26.2.
Can't can can it reach 36.3 can 46.4.
I hope you have it on your diagrams.
56.5 So you can visualize the whole concept about VPNs is you should be able to visualize.
You can see it.
You can do it.
Try to visualize how a packet is going.
Going.
As a graphical representation in your head, try to imagine the packet flow.
That's enough wisdom.
Moving forward.
What we have is I want to go to R1.
I want to create a tunnel from R1.
This is going to be a multi point tunnel, right?
So when I do my interface Channel zero here, my IP address part is going to be the same.
192 168 1.1.
My tunnel source is going to be the same, which is 151 .6.1.
My tunnel destination is not going to be the same because if I choose my tunnel destination, that means
what?
I've already planned it, right?
I've already planned the other end point of the tunnel.
Do I want that?
No.
One side.
Remember, the first side is static.
The other side is going to be that big circle that I created open.
So there is no tunnel.
Destination tunnel mode.
By default, the mode is what?
By default, it's zero or IP.
By default.
We are going to do what?
The problem with this multipoint is now you have to manually tell him what are the other end points?
What are the other end points?
See where the problem comes in.
Not a problem.
We talked about it yesterday too.
Let's say I can figure this.
This is 192 168 1.0 slash 24.
This is dot one.
This is dot two.
Let's talk about these two and maybe dot three.
When I want to send a packet.
Which originates from 1.1 going to 1.2.
1.2168.
1.12192168.
1.2.
It gets encapsulated using what?
What public header source do I use?
What about the destination?
Yesterday.
How did I get this destination from?
It was specified.
Tunnel source was specified.
Tunnel destination was specified.
So I.
New tunnel source was 16.1.
Tunnel destination would be 26.2.
So just forward the packet to 26.2.
Today that is the problem.
I don't have the destination.
I have my source outside source destination part is missing.
But I know that this tunnel is what.
I know that the tunnel is Mgr.
How do I solve the destination part?
Remember this.
If you understand this, you understand Dmvpn, Right.
Also, the other challenge is if I want to go to 1.3.
192 168 1.35.
Want to go to the 1.3.
End point of the tunnel.
What do I use here?
Should be what?
36.4.
Still, that is a challenge.
How do I use two different public IPS for two different destinations?
What they're going to do is based on where I'm going, I'm going to map the public address to it.
I'm going to map the public address to a private address.
I'm going to say, okay, listen, one dot to the address is 26.2.
If you want to go to 1.3, the address is what?
Otherwise the other one is 1.4.
What is the address?
And 1.5 is 36..
I'm going to map it.
This is this this part is the private part.
192.168.1.
This is the private address range.
The other part is the public.
Based on what the destination remember always is based on destination.
If privately the user wants to go to 192 168 1.3.
The outside public address that will be used will be 36.
If it wants to go to 1.4, the address will be 46.4 and so on and so forth based on something let's
call it a table for now.
Who resolves this?
How do you have this table?
We have a protocol which uses.
It's known as.
Next Hop resolution.
Protocol.
Next Hop resolution.
Protocol.
My next hop, which is 192 168 1.2.
I need to resolve the public address of that your resolving the private addresses with the public address
to understand where your tunnel destination is.
So when you configure it, the first thing that you do, I leave these two things right?
I said, Tunnel source.
I said Interface Tunnel zero IP addresses.
This tunnel source is 151 dot 16 dot one tunnel destination.
I did not specify change the mode when you change the mode to mgr.
Mgr does not work without the help of what?
McGarry will not work unless you have np working with.
We will help you to create that table with table private to public.
Okay.
How do you start that table?
IP and network ID?
Then you give a network ID.
What is the network ID?
Just like your IP has autonomous system numbers.
You do router IP ten router IP 20.
This is also a network ID is also just like that.
You enable your process of by saying network ID is this.
Again, there is a difference in the documentation and the way you apply it.
Documentation says that it should be the same or not.
For it to communicate to each other should be the same.
But if you impose it and you keep different ones, it will still work.
So if you want to follow, which we mostly would want to follow the documentation, you would keep it
the same on all of us, on all of the spokes, like just like we would do any.
What network?
I'll say let's say ten.
The moment you do this is on.
Now you need to map.
How do you map and map?
What do you need to map?
192 168 .1.2 is 151 dot 26 dot.
Look at your diagrams.
26 dot.
I map 192
1.3 is 151 dot 36 ..4 is.
Your diary is complete now.
Your diary will use a table called the table.
So
this is the table that your guy uses to go wherever he wants to based on the destination of where you're
trying to go.
One, 221681.2.
It will choose the public address for that interface.
Do you understand the concept of how it works?
That's all I need to care.
If you want me to repeat, I'll repeat any part.
Again, this is your base of MVP, and if you understand this part, you understand how this works.
How?
Right now.
Nothing.
Right now.
Nothing.
You just maps to addresses together.
It just maps.
192 168, 1.221 50.
It just maps it because you gave him the mapping, right?
And it keeps it in a table.
Doesn't know anything internally.
Keeps this in a table.
Then when you're now it has the whole table, right?
Then when you're creating the header, the guy will come here, consult.
Okay.
If I want to go to the 1.2, I want to go to 26 dot.
If I want to go to 1.3, I want to my outside header should be.
36.
Just consult the table.
If you got doesn't cancar just sense it doesn't need to confirm whatever you enter here?
It's static entries, right?
This is a static entry.
Whatever you enter, he'll accept it.
Later.
We'll see dynamic entries where he takes it by itself, but statically you can put it wrong.
Also, in that case, your tunnel will not work.
Right?
It's like adding static entries to a mac address table if you put it wrong or even you put security.
If you put the address wrong, it will not work.
Similarly here you're statically creating the table.
Then Dmvpn is consulting this table.
Your is consulting the table.
It is not.
We need to create the table on all the is good good consideration.
Right.
We need to do it on all the routers, obviously.
How was it scaled?
So that's again, very good.
It's not still scalable.
It still is not.
So we'll have to do something else for scalability.
Right?
INT channel zero IP address 1921681.1
write tunnel.
Source is what?
12.
16.1.
Tunnel destination is not there anymore, so we change it by tunnel mode.
Are.
Since you are not specifying the tunnel destination, what do you do?
IP and IP and network ID say ten.
Then you start mapping IP and map if you want to go to 192 168 1.2.
The next stop is your outside address is $26.
This is 36.34.
Is 36.45.
Is
56 point.
Right.
That's it.
You're done.
Let's move to the other side.
This is our one.
Let's move to our two.
The best part is you could copy paste.
The address is going to be, what, 192 168 1.242.
What is the transpose?
If r two wants to go to 192 168 1.1.
His next stop is 16.
Everything else is the same.
It wants to go to.
Three is public address is 30 6.3.
Four is 46.4.
Five is 56.
Copy it.
Go to A2 and paste it.
Do you think this will work?
1816281.1.
Should work.
Want to have a look at the packet.
Jan.
Axle packet going from 192 and 68, 1.2 to 192 1681.1.
The outside header is resolved to 151 dot 16 dot one.
Source will always remain the same.
Your job is always this part is always.
Remember NP works here and here.
Based on the internal destination, it will give you the external destination based on the inner header.
It will give you the outer header depending upon where you're trying to go.
It's trying to go to 1.1, so the destination will change to 16.
Right.
Let's paste this on all of the others.
This will be 26.2.
Why not?
Yeah.
1.2.
The check.
181681.1 I can communicate 1.2 also I should be able to okay also.
This is for 46.4.
Three will be 36 dot.
These are five quickly.
That.
Then.
Just try and see if it works.
Multiple.
This is a multi point tunnel.
Everybody is using the same IP address.
Subnet.
Subnet is the same.
Endpoint hosts are different, but it is a multi point group.
Right.
Any more questions in here?
The have we solved the problem of having multiple tunnels?
Yes.
So now we don't have to create separate tunnels for each of them.
We can just have one big tunnel and solve everything with mappings.
But the problem of scalability, it is scalable as compared to the old one.
So if the other one could support 3 to 4 tunnels, nice, this one can support more.
The only issue is if you add more what happens?
I have five right now.
I'll add a sixth one.
If I add a sixth one which are seven to the topology.
What am I doing?
This is 67.0.
I need to resolve it on all the routers.
First.
I need to tell R1.
Listen, if you want to go 2.7, your address is 67.7 R2, R3, r4, r5.
I need to tell everybody then r7, I need to make another one, two, three, four five statements.
Five more statements.
The question is not yes, it's fine.
It's easier than before, but I'll add another one.
So I'll have to add six more statements.
I'll add another one.
Seven more statements, 1000 tomorrow.
If I have 1000 strokes, I'll have to have 1000 different mappings on that scope.
And imagine the added load of adding each one line of that command to all of the other 999 scopes.
Quite difficult to do.
Not scalable.
Still not scalable.
Scale.
Not stable.
Do you understand why?
Why is it not scalable at the back?
Do you understand why it's not scalable?
Right.
How do I prevent this?
What do I do?
First of all, I'll clear all of this.
I get all the mappings.
Is better.
Just.
Remove this whole thing.
Dot three.
Then.
Now they won't be able to communicate.
I've removed what my maps.
But remember these mappings, what we did with these mappings, the whole concept behind what we are
trying to do.
Okay.
The next thing that I want to do is we want to do all of this dynamically.
Everything should be dynamic.
How we have a concept by provided again by our one and only NP is known as NS.
Next hop server.
What I could do is I could have this guy R1 act as a next hop.
Next up.
So what does that mean?
That means all the users.
All the other guys.
First of all, I'll have to go to them and point them to the server.
So what they will do is the moment I start on them, they will create a packet in which they mention
that my inside address is 192.
168 .1.3.
My outside address is.
Today.
It's known as Nrhp resolution registration.
Registration request.
The same information that you use to enter here manually on the server.
The same information that you use to enter will be given by R3 dynamically to R1.
You know, the moment you enable all the connections, all these connected devices.
So our phone will take his mapping, R5 will take his mapping, R2 will take his mapping Register with
whom?
I do not know.
Uniqua.
I'll explain how.
I'll explain how the shark is running so we can see those registration requests.
All right, then.
Once everyone has all the mappings, R-1 should be able to communicate to R3.
R2, R5 and R4.
Right.
Let's see how on the NHS.
You don't need to configure anything because people will come and register to them.
Before I do that, let me show you the mappings.
Did I show you the mappings on R1?
I think.
These mappings until now were a wish type.
Static mappings, right.
Because you entered them in the table.
Right now, if you check the table again, you'll see that it's empty.
So.
So it's empty.
The table is still empty.
On this side we call R1 the Hub.
The server is also known as the hub.
On the hub side.
I don't need to configure anything.
I'll go to R2 in the interface Channel zero.
I'll first map it.
I'll say map 192 168 .1.1 is 151 dot 16 dot.
Why do I need to map?
Because when he goes registers he should know the public address of where is he going to register and
then I'll give him the NHS.
I'll say if NHS is remember this is a private address, don't make a mistake here.
Two things I tell him.
I tell him where?
192 168, 1.1 is.
And then I tell him, okay, let me do this.
This is a much easier way of doing it.
Wipe it out.
What I do is I tell them NHS is 192 168 .1.1.
Which is correct.
Is it?
That is my NHS.
Right.
But since this is a private address I need to map it
because he doesn't know where it is.
Right.
I map 192 168 1.1 and it tells him that that guy is 16 dot.
It goes unicast to 16.1 because when he creates the packet of registration, the packet will go from
190 to 168, 1.2 to 2 1.1.
Then he needs to attach
outside of tunnel source will be 26 dot to destination based on 192 168 1.1.
He will choose it as because you have given him a static mapping.
You choose the destination as what 16 dot?
This is the n r p registration.
It's.
Okay.
You can have a look at it this time.
Yeah.
Only the servers across the NHS, which you specify that guy's address has to be written on the spokes
has to be statically entered on the spokes because that's how they'll go and register themselves.
You want to see the registration?
Registration request and registration code is success on the server.
Server reply is saying a successfully.
I've added your registration.
Whatever you told me to register, I've added it.
And what has he added?
If you go to the server and you do a show IP and a dynamic entry either and enter it for 192 168 1.2
The NVM address the public address is what?
26.3.
Have a look at the table and see if you understand.
It will continue.
Nothing.
Again by default.
The guy came who came when I 168 1.2 with his private address and his public address.
And he says, okay, I want to register myself.
La la la la follette's By default, what is AI enabled?
IP Network ten.
Network ten is on.
You need to is just like I said, autonomous system number, just like in network enables, it enables
the whole process of nature.
So you you need that, right?
If you want to have a look at what I did here.
These are my configs.
This is my hub.
R1 is the hub.
That's all I did here.
I did not resolve.
I only have the source.
I don't resolve anything about the destination.
I go to R2, I say IP and IP network ID is ten.
Then I say, okay, go and register yourself.
To whom?
192 160 81..
Since he doesn't know where that guy is, I need to tell him where that guy is.
IP and map.
151.
Not the moment I do this, it knows where to go.
Goes there and registers itself.
What?
Good night.
The decision complete.
Let's do the same thing.
Where?
On the others.
Copy this.
I need to tell them the same thing.
Right.
I need to tell them your NHS is 182 and 68 1.1.
I need to tell them their next stop is 16.1, which is correct for all of them.
Always.
Do you understand at the back what I'm doing?
Stuff that goes down, then we'll have dual hub Hub dungeons can have more than one hubs.
I do is done.
I'll go to 3 or 4.
And I think.
Okay.
The moment I do this, if you check your Wireshark
registration request from R3, request from R4 request from our
is a serial link.
I have connected serial links.
Right.
Is this clear?
Registration request and registration replies.
They've all gone and registered.
I just copied paste.
Copied and pasted the same command and is going to be 1.1.
And for you to reach there.
This is the address.
This is the public address for you to reach the NHS.
So it goes and registers to the NHS if you see our one right now.
Two, three, four, five have come and registered to me.
This entry stays in the table for two hours.
This dynamic entry stays in the table for two hours.
After two hours, the hubs will the spokes will come and register themselves again.
Okay.
Until then, it will stay in that table.
Okay.
You can do that on taxes on right now by default, there's nothing by default.
No, but usually what you would do is you would run on it.
It doesn't work.
You don't use a mjnari or a VPN without the.
Hazards package that works as.
Any questions?
Any part you want me to repeat?
Is this clear what I did?
That's not true.
So looks like.
Yes, Yes, it has to.
Basically, I'm telling him, this is your server.
You have to go register to him.
That's it.
Go to him and tell him what your private and public address is, because it is directly connected to
how this book is advertising.
How?
People are coming to him and registering themselves.
He doesn't care.
Hundreds of people can come just because the registration request comes.
When he gets a request, he accepts it.
When he gets another request, he accepts it.
Right now, the question is, can you send a request to other ones?
Can you register with them?
You can.
If I go to R3 and I give him an R5, we will go and register itself with R5.
Not a problem.
That is what you do for redundancy.
That's how we'll do for redundancy.
But that's later.
Yeah.
If you want to make a design flaw, you would do that, but you wouldn't want to do that.
It's possible.
It's I mean, you can do that, but we will use it in dual hubs when we have two hubs for redundancy.
So one guy will go and register to two people, so one dies, the other one will take over.
Yeah.
How is it a design flaw if you are having you're registering for two people, right?
But then you have to do all the everything here.
It still would work.
What would work?
Let's say you have the exchange would happen.
R5 but later you have a lot of things that you have to do on the hub side.
It's not only this.
You have to run.
You have to run a lot of other things.
So you might design flaw is if you do it on a spoke, if you're pointing it to a spoke, not talking
about the hub.
R5 is a spoke, right?
But when you pointed to a spoke, it automatically becomes a hub.
It will go and register itself.
Yes, R3 will go a register itself with R5.
But again, there's other things that you have to do.
Right now it's not complete.
Right now, nothing is complete.
If you see right now, it's an incomplete.
We have moved from was mappings, only mappings.
Now we are moving to something bigger than that, but it's not complete yet.
It will be complete When what?
When the networks behind will communicate, that is when it will be complete.
So then you can just normally run.
When it is not a normal working, that that's the whole thing about DMV team.
That's why they've included this in your Ccnp routing instruction.
Use the you see any difference between this and the one which you ran before in your tunnels?
There is a difference.
There is a huge difference in the routing protocol that you're going to run.
We'll see that.
But before that, tell me right now, can R1 communicate to everybody?
R1 has the mappings, all of them have the mappings towards R1, so they should be able to communicate,
right?
So if R1 goes and pings
1.21.31.4 and one dot no configuration needed on R1.
So run interface tunnel zero if you see he doesn't have even have the destination mapped, where does
he get all his mappings from?
From the table.
From the end of
in one and in fact.
Know, network 190 to 1.
You know, you have to tweak it.
We'll do that.
That's that's what we're doing today.
That would be the last thing that we have to do before that.
There's another problem I want to talk to.
I want all of them only to talk to R1.
I want them to talk to each other also.
That was the whole point.
What is the point of if I go to all of them and give them the mapping towards R1 and they start talking
to R1?
That's not the point.
I want R2 to talk to R3 for this.
Now.
This process is a little tricky, so keep your concentration and try to understand what I'm trying to
say.
I'll show you not basically just say what I'll do is I'll ping from R2 to R3.
Do you think it will go to R3 to how how the mapping information?
See, when I create the packet for going from 180 to 168 .1.1 and I want to go where
1.2 I want to go to 1.2.
Right.
Header will be added.
Sorry, not 1.1.
Let's say from 1.3.
Jerry header is added.
Source is what?
26.2.
What destination do I use?
When I was going to 1.1, I have the destination in my mappings.
When I go to 1.2, what destination address do I use?
This piece server server would not send, but I can request Stone as a resolution request.
I can send a request to the server and resolution request asking for the public address of whom?
192 168 one.
Not a separate request will be sent.
The request.
Who is?
192 168 1.2.
This request will be sent.
To whom?
Now see the process.
Check the process out.
This is the trick.
The request goes from R2 to hub checks his mappings in the mappings it finds out 192 168.
1.2 is 36 .31. is not looking for two is looking for dot.
Ivan figures out that the address is, what, 36.3?
It does not just reply and tell him it's 36.3.
No.
It forwards this request to 191 51 dot 30 6.3.
Creates a new request, doesn't just forward, it creates a new request meant for 36.3 telling 36.3.
Hey listen, please reply to 153.1. 20 6.2.
Please reply to this guy and tell him what your address is.
The reply goes from R3 straight to.
Pointing in the wrong directions.
Say to whom?
I.
Request.
Request reply.
This is the request.
And this is the.
This is the reply.
The reply should always come from the actual batch, the actual destination.
Then only he will accept it.
If R1 had replied.
R1 would have replied with its own public address in the destination part of his resolution reply that
would not have been acceptable to R2.
R2 should get a reply in which the destination, the source of that packet should be the public address
which is going to take care.
The source is going to be 26 dot 30 6.3.
So when he receives the reply he will get the reply as 36 dot.
Remember again one more time.
R2 wants to communicate to R3.
He wants to go from one dot 2 to 1 dot.
And they'd be doing 68 1.221 92 1681.3.
It doesn't know where 1.3 is, so it goes to the server, asks for 1.3.
The server looks at 1.3 checks.
1.3 is 36.3.
Sends out a request to 36.3 tells it.
Listen.
26.2 is looking for you.
Please reply to him with your private address.
So he creates a packet saying I am 192 168 .1.3 but in this packet it will also have a source and destination.
Right?
The source will be 36.3.
Destination will be this packet will reach what 26 dot 26 or 2.
Will take what this part and put it in his map.
I won't tell them.
Public IP gives them the public IP.
He doesn't go to 192 1681.2.
No, it does.
It's not sending the packet to 192 168 1.2.
This is an IP packet.
It's not tunneled.
Phase one.
We haven't even moved to phase one.
This is not even a VPN
and it's only in here and here.
This is actually replying to the public IP, the public IP of 26.2 and it's specified to R3 by R1 and
it's coming from a source of 192181. no from the public IP.
Yeah.
What?
Question, then ask if you have any confusion, just ask.
I know this is a little tricky.
There is a little trick in there.
That's why I said it in the beginning.
As much as time as this is going to take.
We are not going to move on to finish this unless you understand this.
When actually replies that 2 or 3 replies back to our two, it doesn't reply back to our two, it doesn't
reply back to our two.
R2 never sent a packet to R3.
R1 sends a packet to R3 in that packet.
It says reply to R2.
The public address of R2.
First it goes to remember before going anywhere.
These are packets, these are not tunnel packets, these are not going through the tunnel.
Packets go from public address to public address.
That's it.
They're not tunnel.
They're not going from 192, 168, 1.1 to 1.2 or to 1.2 to 1.3.
No, they are public to public addresses.
How do they know the public addresses?
You've already specified them.
So resolution request, because it knows that the public address for the resolution is 16.1.
So he goes to 16.1, then R1 figures out the public address of 1.3, forwards the packet to 1.3.
But in this packet, what does he say?
Reply to 26.2.
Reply to the public address of 26.
So the packet is created like this coming from 36.3 to 26.2 saying I am
168.1..
Since the public address is 26.2, the source is 36.3.
It moves and goes to.
The song concept will keep on repeating from now until phase three.
Yes, the first bracket is in the pilot.
Which one?
No, this is not.
Not.
Not from private IP.
Still, when you think 192131.3.
Would be a private.
I mean, the ping is kept on hold.
When you ping the first time, the ping will be kept on hold because it would not know where.
1.3 is.
A separate resolution request will go out, resolve itself, and then come back in again.
And once I have that and I do the thing again, it still would be from the private then.
Then once it gets the reply right in his table, it will have the resolution.
Next up is and whatever I do.
After that, it will go directly to that.
After that, it will go down.
Yes, obviously, that's the whole point.
The question is this is not going to be one way because ping is a request and echo reply.
So this guy also needs to reply when he needs to reply.
It would also send a resolution request because it needs to know which address.
1.2.
It needs to deploy from 190 to 168.
1.32.
The reply.
For that reply.
It needs to do the mapping of for that mapping.
What does it do?
Request.
And I will reply directly.
In total.
How many requests are you going to see on this interface?
One, two, three, four.
How many replies on this interface?
On this interface.
One reply.
This direction.
One reply, one reply.
R3 will be replying to R2.
The other one R2 will be replying to Y to two cycles will be here.
Right?
R2 will be sending a packet.
So his resolution will be like that.
When our three has to reply, his resolution will be like that.
But R3 already has information.
No, it doesn't.
Doesn't have it doesn't.
It's just replying to a resolution request.
It has not sent his own request.
You need to send out a request to resolve.
I think that you didn't have information on how to listen to offers.
It doesn't have the information for what I like.
It sends the reply back to you, right?
Yes, it does have the information, but not the private address.
It doesn't know which private address is it replying to is only public to public.
There is no private communication.
These are control plane traffics.
These are all going public to public.
These are not tunnels.
All your traffic is going public to public.
Okay, let's have a recap again.
He actually wants to come to Parliament.
Let's say R2 wants to bring R3.
A reply will also be generated, right?
It's not only just a request, a reply will also be generated as he also needs to reply.
For one thing, the request will be for one when R2 wants to communicate to R3, one side happens,
but since R3 wants to reply back, he needs to know where R2 is private addresses.
He needs a replies one more time R3, R2 wants to send two thing to R3.
What is the packet going to look like?
1.22.
This is the inside packet outside.
What is missing on the outside going from 26 to 2.
This part is missing, so it needs this part.
What does he do for this part?
So request from 26.2 to 16.1 saying who is?
One.
Not kidding.
The request goes out or one creates another request from 16.1 to 36.3.
In this request will be who is 1.3 reply to.
26 dot.
This information will be inside the packet.
Right.
And this is if you check this is control plane traffic.
There is no other header.
There's only one publication.
This will go back to R3 will reply and reply.
I'm not talking about the packet.
The ping has not even come here yet.
The ping is still there, so R3 will send out a reply from 36.3 going to 26.2 because it was mentioned
here saying I am
168 .1.3.
The reply goes straight back.
It receives the public address which is 36.3.
The whole concept is gone.
In the actual header he's going to put what, 36 dot?
So his side is complete.
At the end of this you'll see the mapping has been resolved on R2, only on R2.
The packet.
Now the actual pink packet will go straight, right?
He has 26.323 6.3.
Go straight to.
But our three needs to create a return packet.
Going from where?
1.32.
The reply for that he knows his address is 36.3.
He doesn't know what the address of 1.2 is.
For that, he would send his own request.
Request Reply.
The whole process repeats.
Once he has the mapping, it will stay there for two hours.
For two hours.
He doesn't need to contact the NHS at all.
The whole system is set.
Okay, let's have a look at the ping from our two to our three ping 192 168 1.0 goes through.
This is Wireshark.
This is the other one I need to check.
This is from 3 to 6.
1 to 6.
This is the one which I want to check.
26.2 to 16.1.
What do you see?
A resolution request.
16.12.
36.3.
What do you see?
Still a resolution request.
Why?
Still a resolution request?
I got the request from one end.
I forwarded the request to the other side.
Who am I forwarding it to?
36.3.
I got a request from two R2.
I received that request.
Then I forwarded the request to 36 dot.
You will also see a reply there.
You also see a reply from R3 side.
So if you check the other wireshark, the other capture.
You should see a request coming from R1 to R3 and a reply going straight back.
This one.
It's not.
It's too complicated of a protocol.
Source.
Source Protocol.
Address.
Destination Protocol.
Address.
Right.
So he wants to go from 190 to 1, 68, 1.2 to 1.3.
And the in the frame relation is the public address.
So basically what I'm telling him is reply to 26.2.
And you're saying this I told you in the packet it says reply to which guy.
Right.
You're saying reply to 26.3.
So the reply will go to 26 directly to 26.2.
So if you check from this end, you see the reply is going straight.
Right.
You know, What is it?
The package would be in the packet.
No, usually the packet is not.
I remember the packet is not kept on hold.
The packet goes through the hub first until the resolution takes place.
The packet will go through the pink will go through the hub.
The hub will forward the packet.
There is no delay in.
There is no delay.
Unless.
Until.
Unless the hub resolves the issue, the packet will go to the hub.
The hub will forward the packet just like it forwards.
Any request you can see that.
I think if you go to the first capture.
There you go.
Yeah.
No, no, no.
It doesn't go.
It does.
The public address is the same.
No, this is ICMP and IP has on top, but it doesn't have the IP internal IP is not there.
It's not there.
It's not the actual header that we are talking about because it is a part of interface tunnel zero.
So you have the header, but it's not the source and destination.
It's controlled by traffic, completely pure control plane.
It doesn't work.
This is public to public going from one public address to the other.
Public address.
That's what you see here.
Right.
The first few packets are coming through here.
You see double packets because it's coming in and going out.
If you see this one will be going into that one and this one will be coming back from that one.
36 to 16.1.
Then again, 16.1 to 26.1.
Not the request and the reply.
See, the first packet in
the packet has to go over here.
Right.
The ping will go from 192.168.1.2 to 1.3.
It's going like that.
The first time the public address that is going to be attached to this is going to be from 26.2 to 16.1
because it's going to send it to the server.
The server will check the mappings from the mappings.
He realizes that it's not meant for 16.1.
It's meant for from 16.12.
So this is for the packet ICMP packet unless and until the ARP is get resolved.
The moment gets resolved.
They don't need to go through here anymore.
That's why you see two of them.
One is going in.
One is coming out.
That's why double.
If you check this, you'll see double increase.
Same 3.31 92 168 1.321.21.321.2.
But actually is going from R3 to R1 publicly R3 to R1 and coming back out from R1 to R2.
See your first spring package, which will go from 192.168 .1.2.
Going out where?
I'm not kidding.
What is the public address that is going to be attached to this?
Going from 26.2 to 16.1.
This goes outside.
This goes to R1 outside.
This is.
This is not I'm not talking about the big picture.
I'm talking about the pink package.
Before it gets resolved.
Public to public and private.
Actually, you want to go from private to private.
Isn't it Right.
Your pink goes from where?
What do you pink?
192 168, 1.3.
The source is 192.
168.
This is an ICMP packet.
The actual packet happens in the background.
While this is happening in the chirp is also happening.
This packet goes where to R1?
Right.
It's still ICMP going from 1.2 to 1 dot.
I want realizes that the next hop is 36.3, so it's going to take the packet first, then create the
same packet.
He'll forward it from 16.1 to 36.3.
But when it comes out, you'll see that it's still from 1.2 to 1.3.
That's why on this link you'll see two duplicate packets.
It's not actually duplicate packets.
The public addresses are different.
One is going from R2 to R1, then one is changing.
It is going again from R1 to R3.
But the actual packet is still from 1.2 to 1 dot three.
Okay.
If you want to do it just as it is, you don't have to do anything.
If you just want to configure it, it's done already.
They are communicating to each other.
But to understand how it works is important.
To understand how it works is important.
Right.
I'll repeat it again one last time.
One last time.
What happens is R2 wants to send a ping to R3.
Wants to send a ping to R3.
R2 doesn't have the mapping for R3.
R3 doesn't have the mapping for R2.
They don't know.
They don't know each other.
Specify what?
Woman in.
And when I say something is going through the tunnel.
What is tunnel?
Tunnel means you have an internal IP header and an external IP header.
When you have an internal IP header and an external IP header, that means this tunnel is getting this
traffic is tunnel.
Okay.
That's first this differentiation.
Now, when you are pinging, how does your ping look like?
They have the.
And.
No, I don't.
How does your thing look like?
I said, this is it.
Okay.
This is your ICMP.
He wants to go from where?
1.22 to remember this is 192 168.
When I write something in blue, it's 192 168.
Brown would be the outside hitter.
This will be encapsulated with gray.
Source will be destination.
What destination do I put?
He doesn't know the destination, right?
It's not going to drop the packet or buffer it.
It's not going to drop or buffer it.
It's going to send it where to R1 It's going to send it to R1, Which is what?
16, not the packet.
He doesn't want to drop the packet.
The packet goes to R1, sees the packet.
Since it's meant for him, it opens the packet.
This packet, does it go.
This packet?
Yeah, it is done on two IPS, right?
No, this is not an this is an actual ping.
The actual ping has not come out yet.
I'm explaining how the ping goes.
What happens to the ping?
It's not dropped.
It is still forwarded.
Even if your IP is not resolved even right now, it's not resolved.
Right.
But the ping is still going.
How?
Now, when our one receives it, it checks.
It's going from 1.2 to 1.3.
But this by itself, he is 1.1.
So it's not meant to him for him.
So it sees.
Okay, it wants to go to 1.3.
What is the destination of 1.3 36 dot the source.
It keeps it as itself 16.1 forwards the packet where 2 or 3 three receives the packet opens it completely.
Creates a reply packet going from where to where?
1.321.
Dot.
Does it know where 1.2 is?
It doesn't.
Where is it going to send it to, again?
16.1.
So you'll see.
Source will be.
So your return packet, your ping packet will also come to 16.1 16.1.
You will see the destination is 1.2.
Change it with going from 16.1 to.
So your actual ping, which should have been as simple as this until your end is resolved.
It's not as simple as that.
It goes through the hub.
It's like a man in the middle.
So it goes like that.
The reply also comes like for ICMP before, before the IP.
This is how it goes.
But at the moment this happens.
R2 realizes that he needs to resolve the mapping.
He doesn't want to send all the traffic through the hub.
Then an ARP resolution request is sent from R2.
R2 will say, Listen, I want an ARP.
NHLPA resolution request where it says now this is not a tunnel, traffic resolution is not a tunnel.
It doesn't look like this.
I'll do it right down here so that you know, the difference between the two and a request is going
to look like this.
Talk to me.
Something that happens after the after the after.
The thing is not successful.
The first you send five.
Right.
But then it takes a little while to generate the request.
Until then, 1 or 2 pigs have left already.
So the first cycle is complete silence.
I got replies.
But that's only one thing, right?
How many have you sent?
It's like our pride.
Our puts it on buffer.
That's why I wanted two packets are dropped.
It doesn't want to drop that 1 or 2 packets.
You understand art doesn't have the destination market.
So what does art do that keeps it on hold and waits for the ping to complete?
Best for the art to come back until that time, the ICMP times out.
I don't want to time that out here.
I want.
If you don't have the mapping, send it to the server.
He'll manage it.
He'll send it to the actual destination until your mappings get resolved.
Are you asking
if I will be going to reply.
Will also be going to either the.
Yes.
Even as long as R3 has not resolved its mapping, the reply will come from other.
R2 will send the request from R1 and R2 will also reply back from R1.
R3 will also reply back from As long as both sides have not resolved their mappings to resolve the mappings.
The app looks like this.
Who is 1.3?
What's the final thing is?
Yeah, both of them.
That's what you see in Wireshark.
They are simultaneous.
You check things are also going resolution request is also in the.
This is the pink.
This is the resolution request.
They both come out together, actually.
The pink comes out.
The resolution request comes out.
As long as the resolution request is not replied with, the pink will go through the hub.
The moment it is replied, they'll go directly.
Okay.
So we see a change in.
First off, what do these do you mean?
Are.
This one.
This one is going from 2 to 1, then the other one is coming back from R1, R2, R3, R1 acts as a mediator.
So it is acting as a mediator, right?
It's actually going from 1.2 to 1.3, but first it enters R1, then it leaves from R1.
Guilleuma.
This is the ping request.
Ping request going from 2 to 3.
But first is going from where?
26.2 to 16.1.
Then from 16.1 to 36.
Same request coming in, going out.
Then goes back to the destination.
Same thing happens to the reply coming from 36.3 to 16.1.
Then from 16.1 to 26.2.
Coming in from one end, going to the other side.
Coming in from this side.
Going to the other side.
In the meantime, resolution request has also come through.
How does the resolution request look like?
Who is 1.3?
And this is not tunnel traffic.
So there is no IP inside here.
This is just control plane asking who is this guy?
Who is this guy?
Right on top of that.
What I'll do is I'll add a header.
This request will go straight to the server from 26.2 going to.
The state request to the server.
Listen, man, I want to know where 1.3 is.
This is a resolution request.
I'm sending packets to him, but I'm sending it through you.
I don't want to send it through you.
Please tell me where that guy is.
What does one do with this packet?
Sauer to R3, but adds another piece of information in there.
What?
I will forward it.
But add another piece of information here saying.
Reply 226 dot.
The request comes here.
The reply.
Now, the request will not look from 26.2 to 16.1.
The request will be from 16.1 to 36 point.
The request comes.
It says, Who is are you?
192 168 1.3.
If you are reply to 26.2 send as we call it, resolution reply, send a resolution reply back to $26.
The resolution reply is generated on our three.
Resolution reply says okay, I am on 92 168 .1.3 My source Just like earlier resolution requests and
reply used to take place by actual source is 36.3 and I'm going to 26.2.
So it goes to 26.2 times.
Listen, I am I am on 9268 1.3.
So later now I want to send a packet to 168.
1.3 is is going to send it directly to.
$36.
And that's what you see now.
All the other corresponding packets which come out from R3 or R2, will not go through the hub.
This is the hub.
They don't go through the hub as many number of packets you send.
It will never go through the hub again.
It doesn't need to go through the hub.
Right.
If you check they're all going spoke to spoke directly.
Spoke to Spoke.
Right.
It applies from 3 to 2 is the old one.
There as many packets as you send now they will go straight.
Why take this out on R2?
R2, I have a static mapping for the server.
I also have a dynamic mapping.
For whom?
How did I get it?
I sent a resolution request.
Request went to the other side.
The guy replied to me.
There are two different things and this time the two request request reply.
In the meantime, the ping will also go through the hub the same way.
The moment the request reply comes to me, I have the destination address directly.
Now the ping will not go to the server now it will go direct.
Any questions?
Well is sending the packet first.
His request was Rover initiates the session.
We check our tools, R3 will also be resolved.
So it is also resolved.
One 168 1.24 R3 is absorbed as well as four R2.
Both sides resolved.
Any questions?
No questions.
Only two hours.
The whole process will start again after two hours.
The whole process.
The first things will go through.
The hub request will be sent, reply will come back.
But it's a very small process, just 2 or 3 packets.
It happens within two seconds.
The whole process of request reply happens within two seconds.
By the end of that post.
Communication is there.
The good thing is I did not need to configure anything I can communicate anywhere.
1.4 and we send out a packet to 1.4.
You'll see for resolution requests.
Right.
I told you both ways.
One is this way.
The other is so this way and this way.
One resolution request comes from R4.
Forward it to R3.
The other resolution request comes from R3.
Forward it to R4 because both sides mapping should be resolved.
Right?
The whole process is repeating and you see some things going up and down here.
Two things.
Only one, this was even quicker than that.
Only one thing went through the hub.
Again, I want to go to 1.5, see the hub again.
Resolution.
Request.
Resolution Request.
Resolution.
Resolution Request.
Resolution request.
You already has the other one.
Right.
By the time this is done, you'll see.
So it has everything because everybody communicated to him.
Imagine how scalable this is.
What scalable.
I did not configure anything on the scope.
This is all I did.
That's all I did.
I just told them to register to the NHS.
All of them registered and the good thing for them the NHS is like your godfather.
For them it's like community NHS.
R1 is the Godfather.
Now they want to talk to each other and they don't know the address of the guy.
They will go to the Godfather.
They go to the NHS and tell me where this guy is.
The NHS forwards.
The request tells the other guy, Hey, listen, please talk to him.
Go and tell him where you live.
He doesn't go back to him and tells him, Listen, this is the guy.
No.
I ask him, Where is this guy?
I'll go to the other guy.
Listen, please reply to that guy.
I don't have time.
Then the other guy asked me, Do you know where this guy is?
I'll go to him.
I'll tell him.
Listen, reply to this guy.
So it's a cycle.
Think of it as a loop.
Request.
Reply.
Request.
Reply.
Total of six packets.
The hub will see four.
The spokes will see two.
There is this part clear.
This is complete DMV.
We still have not created the communication set yet, but most of your dmvpn concepts are done here.
The single hub, be it dual hub if you understand this part.
Let's take a break.
Now is 1015.
Let's take a 15 minutes break.