You want to use stacking technology you need to buy the right switches so essentially you need to buy
the right product for the feature that you want.
As I mentioned Cisco have supported stacking for a long time so just such as the 30 750 have supported
tech wise for many years.
Yes some examples flics Steck was introduced in 2010 flex stack plus was introduced in 2013.
The switches that support flex stack all the 29 60 yes and 29 60 x 4 flex stack plus you need a 29 60
x or 29 60 x are the speed of a single stack length in both directions.
We're using full duplex is 10 gigabits per second for flex stack and 20 gigabits per second for flex
stack plus the maximum number of switches supported in one stack is full for flex stack and 8 for flex
stack plus in the real world.
Have a look on the Cisco documentation and the data sheets for any switch that you want to buy to ensure
that it supports the speeds and capabilities that you need.
Now Chessie aggregation is another Cisco technology which allows you to make multiple switches operate
as a single switch from a big picture perspective.
In a lot of cases such stacking is used after the Access Layer whereas Shecky aggregation is used for
more powerful switches used in the distribution and core layers.
So in summary Shashi aggregation is used for high end switches as an example Chessie based switches
used in the distribution and code layers of Kempis networks.
It does not require special hardware adapters but rather uses Ethan interfaces on switches.
It typically aggregates only two switches.
It's more complex to configure but provides more options.
Now from a big picture point of view Chessie aggregation is the same as switch stacking multiple switches
act as one switch which gives you both availability and design advantages.
However one of the big reasons for Shishi based aggregation is high availability design's technology
such as Cisco virtual switching system or VSS is supported on the Cisco Sixty five hundred and sixty
800 series switches.
Have a look and Cisco's Web site for more details.
But just a quick overview.
Now even if you're not using Chessie aggregation you need high availability in the core and distribution
layer of your network.
As discussed one of the reasons for having multiple switches in the distribution or Colyer is to provide
redundancy in case one of those switches goes down.
So we use technology such as HAARP spanning tree and others to provide better redundancy and better
scalability.
However the downside is cost you need additional switches and it's also more complex to configure.
You need to think about where you put your spending tree roots as well as your aitches Oppy active Araud
is now Chessie based switch typically has multiple line conc one or more supervised modules and one
or more power supplies for redundancy you want redundant power supplies you want redundant supervisors
and you want a multiple line Conte's in your Chessie.
The idea with supervisor modules is if one of the supervisors goes down the other one can take over
the management of the switch a supervisor a module essentially the brain for the Chessie based switch.
If you lose your supervisor the switch will have no brain.
Hence you have redundant supervisor modules in your switch.
You have redundant power supplies in case there's a problem with one of the power supplies.
And in addition you'll have multiple connections from your access layer to multiple line cards using
linked aggregation to ensure that if one of the line cards goes down the network can continue functioning
using the redundant line card.
Now with Chessie based aggregation what we're doing is taking multiple chassis based switches and using
either relate to through a channel between multiple Chessie based switches to provide better redundancy
and better throughput to the distribution core of the network.
I've discussed that in a lot of detail in the campus videos that make up of course what we can do is
take that a step further and instead of using linked aggregation between the chassis base switches with
spending tree NHS opii we make the chassis based switches appear to be a single switch in the model
on the left the two switches are independent of one another.
They run their own Mac address tables.
They run the own instance of the spending tree.
They essentially act totally independently of one another.
You configure two separate switches in the example and you configure them independently of each other
with an aggregated Chessie environment.
However the switches appear to be one switch to the rest of the network.
You can have multiple physical ports going to different physical switches but you can aggregate them
together using multi Chessie eith a channel because logically a one has two physical connections to
the same switch even though physically its two physical connections to different switches and the different
ways to implement this.
We can use multi Chessie isa channel but use an active standby control plane where one of the payes
acts as the switch for the control plane protocols.
So one of the switches is in control of spending triva ether channel up and running protocols.
But to take advantage of the fording power of the supervisor modules on both switches we have active
active data planes.
We are lead to forwarding and Leia's free forwarding is done by both switches.
The switches synchronize their mac address tables and rotting tables to support this there's a single
switch management plan however.
In other words you manage both switches on the active switch when you change the config of the active
switch.
That configuration is synchronized automatically with the standby switch.
Now you could take us a step further where you have an aggregated virtual switch and an aggregated access
switch.
Physically We've got two switches in the distribution layer not but by using Chessie aggregation and
they appear to be one switch to the Access Layer we have four physical switches but they appear to be
a single virtual switch and then we can run a physical ports in a single ether channel between the distribution
layer and access layer.
And in that case we don't need spanning tree because even though physically we have six switches virtually
We only have two switches with one virtual cable between them.
As always there are caveats and things to be aware of when doing this.
But that's the ultimate vision of a linked aggregation with shishya aggregation and switch stacking.
You're aggregating your physical distribution switches into one virtual switch and you're stacking your
access switches into one virtual switch the simplifies the network because you don't have to worry about
optimizing spanning tree and optimizing HAARP.
There's no need for US IP because we have one virtual aggregates which we would still run spending tree
in case there are problems.
But from a spending tree point of view both of these ports are forwarding because there's only one logical
cable between the two switches.
It really simplifies the management and configuration of a campus network.
So in summary stacking technologies and chessy aggregation technologies allow you to simplify the management
and configuration as well as the forwarding of traffic in an Ethernet network.