This action will study that how we deal zero and Tier 1 architecture NSX providing us fully distributed
two tier routing architecture and one thing it's very important to note here.
And let me highlight that that to the NSX.
The idea behind the routing is that it is motivated to do all the routing facilities closest just to
the source.
So whenever the routing lookup happens it happens closest to the source.
That's one of the key we have.
Apart from that when we have the cleared architecture we will see that how the routing would be simplified.
So let me show you in the next diagram here in this diagram we can clearly see that you have tiered
architecture architecture you have been in when you have been in two and this is something as if for
example logical will but if you see the copy of this particular logical view in transport nodes you
will find that one copy is showing with hypervisor one so inside the hypervisor one you have been in
2010 two other copying or other instance for hypervisor too you can see here that we have VM to posted
on hypervisor to there also we have been in 2010 too and both the places you have the tiered architecture.
So here you can see that we have Tier 1 and here you have two years zero and these copies are there
for all the hypervisor.
So hypervisor they can think their own routing and routing is in two tiered architecture.
Now suppose for example VM one wants to communicate with William three then how the routing lookup will
happen.
So obviously what will happen because this all the ideas that you are seeing here either Tier 1 and
2 or 3 0 and Tier 1 they are local to the hypervisor correct means they have the kernel module installed
inside the hypervisor know what is happening there.
Suppose he wants to communicate to this particular IP first of all he will connect to his own gateway
not a gateway what he will do he will contact and check or do I have a routing Hey Tier 0 I have advertising
you my connected outs and other service roads to do you how do you know that how to reach to William
through this IP and then he will forward that request to other side.
That is the can into there and then it will reach to their destination.
Correct.
So in this way you can see that even your packet is not leaving hypervisor one because all the routing
is happening local to hypervisor number one.
Same thing same explanation here you can see.
So William one wants to send a VM one is in tenant one sends packet to VM three this is their destination
and turning to the packages saying it's the gateway that is your tenant to index nothing but your local
Tier One day years.
Let me show you again here in this diagram you can see that you are sending the two different tenants.
It is something like entertainment and communication happening over hypervisor one know what is happening
that there are tier one beer they are sending that package to Tier 0 they're following the refined road
and we know that we have internal connectivity between ti 1 and 0.
We have seen this earlier and in upcoming sections also I'll show you that how tier zero and Tier 1
they are connected.
Now once the packet is reaching to tier dealer what else is doing that routing loop lookup happens acting
on zero dear data mines that this IP subnet is alone from turning to tier 1 data and the packet is out
there so he knows that whatever request I got from say for example Tier 1 This is nothing but setting
and one and then he hairy again you have Tier 1 and this is nothing but and 2.
This is my Tier 0 router.
So once we know that okay this is learned from the net number two and tier 1.0 then it forward that
packet towards the destination.
So routing look will happen again and to the idea.
This remind that this subnet is directly connected to look up this platform and then whatever logical
subnet it has are suddenly connected with the logical switch it will forward that packet to that particular
subnet to that particular VM to more precise and in the reverse we also the same thing will happen.
So return traffic again will come here and go to a Tier 0 and then again it will go to the through and
then into an end destination it released destination to one thing you can see irrespective of different
tenants your packet never leaves your hypervisor kernel model correct.
Now what will be the case there to your destination will be in different type of visor so how the packet
flow will happen.
So let's see this.
Now here we can see that diagram is like very busy but what is happening suppose William one wants to
communicate with William too that is over other hypervisor correct.
So in that case what will happen.
This is quite interesting use case so what will happen here again see that we have different dealings
and you have different hypervisor as well so let's see that how the packet will flow.
So first of all he wants to communicate with this particular destination.
He will send his query to the Gateway gate we will send his query to the Tier 0 dear dear dear now dear
dear dear.
He has to figure out that for this particular destination belongs to kin and to so he will go and conserved
hypervisor one name two tier one data.
That means this guy no one's the package will reach end to the year when these are then he will see
he will do the look up and he will calculate or this particular destination is on other hypervisor here
it should be hypervisor too.
So this is on other hypervisor and the other hypervisor with Tier 2 retaining two tier windier good
to know what will happen exactly.
Here that at this point of time this particular day are because this is posted over hypervisor one and
this particular dear that is whose straight on hypervisor 2 this is true.
So today what do we do that they will form panel in between them so form internal means what it.
What will happen that whatever source and destination.
So you have your source IP you have your destination the actual source and actual destination IP they
will be encapsulated inside the Cape Argus so whatever source ship and destination tap is their six
point ninety two and then packet will get encapsulated and it will be forwarded to this particular gear.
Now I disagree I will do this here.
We do capsules this packet and then he will do a two lookup bottom and he will identify in which particular
subject that I have this particular source belongs to.
So he will forward that frame.
He will forward that packet to that.
We aim to target and in the reverse also the same thing will happen so in the reverse direction what
will happen in the reverse direction also when the packet will come it will go and query 2 2 2 the Tier
0 then it will go and the KRG rule will query to this particular this particular site in in 2020.
And now this team into India.
He will form the panel in between these two devices.
So you have to.
Let me try to go in like this.
They will form actually tunnel and then they will do the encapsulation in the reverse order.
So this time the source will be this IP.
The destination will be out eleven this IP and then they they will put this all step.
And so for example type 1 and 2 and then packet will go at this point.
He will recalculate the package to encapsulation and the absolution will happen across different different
tier 1.
Let me quickly show you all these mechanism that we have I guess comes from William when do we aim to
see where you can see that it will send the packet to the Gateway now gateway.
He has the default road towards the Tier 0 so he will forward that package there.
Now Tier 0 dear he will get to mind that this belongs to and to deal 1.
Then he will go and do the query to the tenant to clear when d'ya know what will happen.
That tenant to dear will do they look up and he will find all this is belonging to hypervisor 2 I am
hypervisor 1 but we are in the same dinner.
So what will happen there to keep encapsulation so hypervisor one will encapsulate and it will send
that to the hypervisor to DP because they will find the tunnel in between them then hypervisor to they
will dig capsules the packet and then the packet will deliver to the VM too.
So this is a you can see the power and the logic behind this make it your architecture Tier 0 and Tier
1 with multiple tenants.
So this will be the flow of packets so you hope you understand understanding it is actually a very important
section that we have completed here.
So let's stop here.