Noted that each stacking module has two ports with which it's used to connect to another switches docking
module.
So as an example if you've got four switches each switch has a stacking module and four cables are used
to connect the force switches together the way you think of this is the switches are a stack of switches
in the same rack.
One of the reasons for doing that is that the stacking cables are very short in length so it's expected
that the switches are physically positioned next to each other.
On top of each other as an example some of the Cisco stacking cables are only half a metre in length
or one metre in length or three metres in length.
Again you need to think of a switch stack as a logical single switch.
You may have four physical switches but logically they're acting as one switch.
One of the switches in the stack becomes the stack master and it's used to control the rest of the switches
in the stack.
The physical stacking cables connect the physical switches to each other and allow for communication
between the switches and the stack.
But the monster switches in control of the stack.
If as an example you have four switches in a stack and a frame arrives on switch for and each to exit
out a switch.
Three to switch one is the master switch switches one three and four all need to communicate over the
stack links to forward the frame switches one three and four would need to communicate with each other
over the stack links to forward the frame switch one being the monster switch would match the Ethan
at frame to the MAC address table and would then decide out of which port to forward the frame.
Think of the master switches the brain of the stack logically in a topology like this.
We have two physical switches.
But logically they are a single switch and the same would be true if we had four switches in a topology
like this we may have four access switches connected via stacking cables.
So physically it would look like this
but logically it looks like this.
The switches appear to be a single switch to the rest of the network and you configure them as if they
are a single switch.
We now have four uplinks to each distribution switch.
So physically they're connected as follows.
With each access switch having one connection to each distribution's switch but logically we have four
physical cables to each distribution switch which then allows us to use either channel to the distribution
switch.
So rather than using spanning tree across these uplinks we're one of the porters forwarding and one
of the ports is blocking.
We've now created an ether channel to each distribution switch.
This kind of setup simplifies the configuration and management of the network from a spinning tree point
of view rather than having six switches involved in the spending tree.
We now only have three switches involved in the spending tree.
So it's much easier to configure.
Much easier to understand as well as to predict what happens when there's a failure in the network uploading
across an ether channel.
He's also more efficient than using spanning tree to block one port and forward on another port.