In this lesson let us discuss about north to south routing by service router who on edge node.
So we are going to see their direction and what is happening what type of encapsulation encapsulation
and how the packet is flowing from north to south and then south to north.
Here you can see the physical topology if we want to communicate that your request from the VM go to
the local switch from local switch.
It will go to the DIA from DIA.
It will go to the Edge edge where you have the Acer and then it will go to the outside.
That will be the flu.
Here you can see that your data is a kernel module over compute hypervisor and your edge is there in
the infrastructure cluster in the management controller and in that particular cluster even I will see
that in the lab section I'll show you that topology one more time that where we have the Williams and
the DIA and will we have the is our India in the edge so this is the topology.
Let me go and show you the flow of traffic in this particular topology.
So here you can see that the web.
So here is the Web.
Having IP 172 wins extend out eleven and Mac virtual Mac or the macro.
This is Mach 1.
He wants to communicate with outside.
He wants to go outside.
So what will happen how the traffic will flow.
We will see each and everything.
So first of all it will go and connect to its gateway.
Gateway is this particular idea and is the local routing.
It has a local gateway.
Now what will happen in the destination IP.
He can see that all this IP is belonging to 1 9 2 2 1 6 8 100 something so a 92 1 6 at 100 or something.
That is not there.
In my local subnet that is not there in my road lookup I am not able to find it.
Then he will go and contact the ESA.
No one he will go and reach the ESA.
Here you can see that in between.
So we have two type of people here.
We have E6 I type address and then here we have the edge each edge gap.
That's a change we have that we have discussing in our previous sections in the initial sessions that
now the exit devices they can do encapsulation encapsulation.
And next the challenge we have in two or three words to work for.
So edge devices.
Now they have the intelligence key that they can do the encapsulation and up absolution So what is happening
here that the actual source and destination IP or whatever payload was there that will be encapsulated
inside the DP With the help of G leave encapsulation.
So this source destination.
So this TB Atlas will go and reach here.
So you have done the encapsulation means yes I D has type has gone the encapsulation and then it step
will do the data absolution once you open the packet also see or the destination IP is belonging to
for example 1 9 2 ones 6 x something now to reach 2 that IP now this responsibility of the ESA that
is our we know that as I can run this static load on widget road so Israel can get a mine or this IP
I can reach via one 90 to 1 6 8 2 4 0 dark 1 that's the gateway to reach to a 92 1 6 830.
Now here we have the detailed explanation of whatever we have seen so Web wants to communicate with
this IP it will connect to the Gateway.
Step number one now the DEA don't have the clout to reach to that.
So he will go and contact to the Issa then we have the Geneva encapsulation in between that actual payload
will be forwarded over this source IP the source of DP and destination of DP pages.
Now what will happen that the edge node we deem capsule in the packet and then it will send to the ESA
this thing.
Also we have discussed now the is performer out in look up and the combined they wrote this belonging
to this gateway.
Now the packet is sent on the relearned segment to the physical outer and finally delivered to this
IP so these are the steps and you can pass the recording and you can make a note in your notebook so
you can draw this particular diagram and then you can make all the steps that you can see here.
Now what about the return traffic when the traffic is coming from here and this time to where the one
that's IP is this.
So in that case we can see the flow of the packet first of all the packet will go and hit the ESA.
So Acer because Assad is the link that is export to the external device.
So now what will happen is that the local lookup will happen single lookup actually will happen at the
R D are labeled at this point.
Now when they see this particular look up they see all this destination IP address and this destination
IP address is belonging to up because remember they are learning the means these devices they are learning
the DP to Mac are the virtual Mac IP from the central controller.
So either that will be there in the local control or they will learn the key to the Mac resolution and
marketable from the control plane.
So now the user will think Oh I will.
He will be confirmed that this particular IP is belonging to which particular DP then the Geneva they
will do the encapsulation.
So now the edgy device edge will do the encapsulation the source will be his DPR this destination will
be the E6 I Cape Argus and The pocket a packet will be forwarded to to this gear.
Now in the packet will come to this idea then what will happen this deal will not do the lookup because
the lookup has already done near to the source.
So here you can see all these important things that can look up is happening near to the source all
which so near the source and there are so many things that we can go and write it and papers the lookup
is happening near to the source.
This is our devices having services and the idea going up and the routing lookup and the DP.
Now the edge devices can do the DP encapsulation decouple solution.
The idea is are they can be host they are whole straight over edge and this D are is the kernel module
over the years access so these are the important and high points we have that is very different in other
and solution.
So now already lookup has happened.
Now he will see that.
Okay.
Which particular segment had this particular macro.
Does this particular IP address.
And then he will forward the packet and in this way the destination to source packet flow will happen.
So now whatever I explained the same thing as written here.
Again you can if you want you can pause the recording and make an authentic and go all the six steps.
So this is a way that will help Officer the lookup is happening and source to destination and destination
2.
So spectacularly it's happening.