In this section and coming sections we are going to study about high ability and easy ESPN will perform
the lab task as well.
So we have two type of two options actually in high ability either active active active or standby.
Now here you can see that since the services are run on a cell component the SL component is running
the services on Tier 0 or Tier 1 gateway.
The falling concept is relevant to.
This is our services it runs on edge node and has two more days of operation so as I told you.
Active active active standby and belonging to ESA.
This is the ESA component now.
What's the difference in active active and active a standby.
And that's actually true for not only for NSX but any type of any type of ASEAN solution.
What is happening.
Suppose if we have two component let me change the color.
Suppose I have two components to is our So for example is our one and is are two and if they are working
as an active active.
So for example active active and suppose if we do not have any interconnection on any link.
Who is the replicating all the estate information.
Suppose we have a state connection going outside.
Some applications are going from south to north.
Some a straight full inspection.
Some lacks service some firewall services enable and this because firewall and not all those services
they are maintaining some estate.
These are state if they are not replicating to other active link that means if any failure is there
you will lose their strictness correct.
And in say in between if we have any replication link who will replicate the state.
So for example some other Cisco technology they are thinking the AAP they will IBM is snooping into
electrical etc here is not the case.
So that's why it is a stateless.
The active active it will give you good level of redundancy but you can do a state full type of designing
as a stateless on other hand.
The active passive is we'll see that that's respectful.
So they will maintain their state why they will maintain their state will discuss active activities
the stateless way because they are unable to crack the connection sequence number etc. from 2.5 am active
active each year more does not support a state full services they are not supporting its critical services
that whatever we have discussed that was true.
Now here you can see the diagram in this diagram you can see clearly that you have two active active
linked connected with two physical rotate so physically this is like this logically you have a sir and
you have the edge node one and as you know two they are connecting with two separate logical entities
logically it will look like this no problem this is the active active know what is happening that we
know that we can have inter is our routing so we know these things so far that to the T G ro devices
devices belonging to t 0 so is devices there inside t 0 0 they can run i.e. BGP also in between them.
So not really they are supporting the ECB but they can run I BGP as well.
No I state wonders of this particular scenario with running a BGP is.
So let me highlight so to provide a redundancy for fiscal road to failure.
The idea is are on both is must establish the routing agency to the fiscal rotor.
Are you are these fiscal voters may or may not have the same routing information.
So when you have beer it physical outer one fiscal outlook to maybe he submit is different maybe he
submitted is different and that's the way they can cause some sort of asymmetry so for such asymmetry
to policy users can enable into a cell routing.
This feature is also available on this feature actually is one live level on Tier 0 gateway that we
have discussed earlier in active active hieroglyph mode.
Now we'll see their diagram for this so we'll go and check their diagram
I have a diagram here I can see that in the active active mode so I'll come to that diagram before that.
So Intel is a routing is enabled by user and overlay segment is R2 plumbed it's okay that we know that
we can go and create this particular connection between the NSA does something like in quelling an ABC
decision is automatically created by 2018 you are not bond devices EVP and abstracting out without doing
these routing exchanges.
So what is happening here.
Let me now quickly show you this diagram.
So now you can see that in case of active active routing you have this i.e. BGP in between these devices
and then or what will happen actually that they will think the BGP and others because both are active
both can forward.
So both should have knowledge of complete BGP table so again this is completely routing thing.
Whatever we studying in routing so generally for higher probability in traditional routing in Cisco
routing we know this thing that in-between devices we are appearing with IBP and then their devices
can go and form EVP the same type of logic we have here.
And here you can see that you have high use level of rigor Nancy you can think this like this is our
USP one I use to at the moment and you can see that we have highest level of Oregon Nancy in this way.
Well this was the high higher ability that in days of active active you have this type of features and
features and you can see an act
BGP setup.
But the only thing that we can see here is not there is that they are not distasteful.
That's the only drawback we have means they can do a state full failover switch various etc. so they
can only inspect the Packard to their escape list.
Actually this active active is nothing but a stateless feature.
Expect less design.
Now we'll go and check the active will stand by what is happening in this case that these are the high
ability mode where only one side is active and they can do this just take full service.
That's the key here.
So they have this a state full service and that is enabled and they can have decision table and all
those state full packets they can track they can maintain now default multiple get reconfigure active
a standby.
Here you can see another logic here is that you have two devices.
One is active one is the standby.
That means always the packet is going from active member correct.
And we study these things inside say for example we are IP or it is IAP that's suppose one is active
one is when it is standby if suppose active will go down then the scan will become active and it will
start sending the traffic same is the case here also you can see that to a default mode will get reconfigured
in active with standby.
Let me use this ability configuration is non preemptive a user need to select the preferred member when
Gateway is configuring in the active a standby.
So we have to select as a user as the admin I have to select who is the active and who is the standby
will enable preemptive behavior allow a is out to resume active role on preferred as you know as in
recovers from failure.
So BGP itself has a whole load timer of three minute.
Correct.
So suppose if one of the links will go down BGP has to weaken words to start the session correct.
And because BGP is slow protocol so there will be orders to be very honest.
All right then we'll see that we have one level so we'll make one of the device down.
And BGP will weaken worse.
And this is not because my device my tier zero mightier when devices are going down or up.
This is because the protocol itself is slow and slow to converge.
Now for tier one gateway use the regular activists can by is has the same IP address not on only the
active Assad will reply to our request while the standby by our interface operational estate is sick
as gowns so that they will automatically drop the packet 40 0 gate to actively stand by as I have different
IP addresses northbound and have e BGP session established in both the link both of the tier zero is
are active and ask Istanbul receive routing updates from the physical router and aggregates out of his
of just how this can be.
Tier dealers are prepaid says local is here you can see the difference there so you read out all is
fine so you can see their good friends many are enabling the feature in Tier 1 Gateway when you're enabling
the active a feature and as you look at what is happening in case of the Year Zero
that in case of the year zero what is happening down to the standby to your dealer as are prepaid is
local is three times in the BGP appear to that traffic from the fiscal rotor prefer the active to zero
automatically they will make that route back or that particular road back so it will automatically prefer
the active active link or active Gateway and that's very much that we are struggling in BGP that if
we want to do part selection you have multiple ways and here because one I have to make that as a standby
so I will wash in the BGP part or make make the recipe part of Rs 2 3 times the local is prepaid and
the path will become back.
Now this outbound IP address on the active and the standby tiers it is our same.
So most of the things are saying there is no much change here.
Now here you can see that we have two different IP addresses by two in the age Node 1 and is not 2.
One is at two and one is a standby.
Here you can see the standby link or what it is doing that automatically bleeping local is three times.
So this will become standby and this will be the active All right.
So this was the high availability and how NSX keep providing different type of methodology with higher
ability.
Next section what we do will go and perform the lab related to higher ability and we will check the
ECM MP as well.