Hello one more come to see CNPC which course prepared by or Khail Cisco do I get to see sandpits certification
exam to in three parts and are Savitch route and T-shirt and we are starting with this be part and this
first section will be about the basic switching concepts.
We are starting with the harp harp is a common connection point for devices work and hubs that the word
is commonly used to connect segments of a local area network.
The Hub contains multiple ports.
When a packet Arabs as one port it is applied to the other port so that all segments of the local learn
and work can see all packets as you see them in the picture river hop.
And we hear for ports over to Devizes
if port one wants to communicate with port for for example the peccant is Flude to put two and Port
three as well.
And as you can see that that's an inefficient use of the bandwidth.
The second one is we are going to talk about is Savitch and networks which is a computer networking
device that connects devices together on a computer network by using packet switching to receive process
and forward data to destination device and networks which is a multiple or bridge that uses hardware
addresses to process and forward data at Linklater layer two of the PSI module and you can see a switch
in here.
This switch can be oversight layer two or layer tree as well.
If you're are talking about the layered pre-speech that's a multilayer switch which can also make robing
as well later.
So it's make switching beds when they make table.
They keep mac address stable.
And forward the pickup's imports using that make up a stable so that provides efficient use of bandwidth
and these devices can also provide power over the Internet and the security operations for us which
we are going to talk about later in detail.
Let's take a look to the broadcast domain or broadcast domain is a logical division of a computer network
image all nodes courage each other by Bob Keth at datalink layer broadcast domain can be within the
same law clarionet or segment or it can be bridged to other local area network segments.
Any computer connected to the same switch is a member of the same broadcast domain.
Further any computer connected to the same set of interconnected surveys is a member of the same broadcast
domain.
Please pay attention that others and other high later devices form boundaries between Burgas estimates
and separating villans the way it's broadcast domains as well.
Let's take a look to the picture now.
We have four both Testament's answer.
We have read the broadcast domains in here and as you can see that we have bandwidth twice the which
is rather in here and also Whelan's are boundaries for the broadcast domain too.
Let's take a look to the MAC addresses now.
And Mekka address are for computer or printer or something.
Any network device is a six byte unique identifier assigned to network interfaces for communications
at that layer of a network segment.
Megadoses are used as the network arrests for most terribly new technologies including Internet and
Wi-Fi logically Meka addresses are used in the media access control protocols some layer of the was-I
module and organisationally unique identifier is a 24 bit number that uniquely identifies a vendor manufacturer
or other organization as you can see that the first portion of the MAC address is organizationally unique
identifier.
Other portion of the MAC address is universally administered address universally administered Everest's
is uniquely assigned to a device by its manufacturer and that's it.
And that's the second portion.
Let's take a look at the Internet frame right now.
It's in that frame consists some Feltz as you can see that in the picture they are pre-amble SFD we
see where Mac Sendler Mac an optional relend tech and type filled payload and CRC checksum.
For example let's take a look to the preamble first.
Preamble communicates to the receiving devices whether a frame is coming and pro-white synchronization.
The second fill is SFD we just start afresh.
Delamater start him.
Delegate who is responsible for specifying the beginning of the destination MAC address in the next
byte and the other fields are receiver and sender Mac and an optional will intact and reheard type field
in here.
And we have a payload pad and CRC checksum.
Let's take a look to the basics which you persist right now if the destination Meka is found in the
camp table of the switch.
The switch says the frame out of the corresponding port.
This process is called forwarding.
If the destination MAC address cannot be found in the camp table the form is sent to all other ports
in the same Bil'in and this process is called Food Inc.
If the destination MAC address of the receiving frame is the broadcast address which is
f f f f f f f f f f f f this time the frame is sent to all the ports in the same villain.
And this process is called also floating.