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Basics of Bridge

hello everyone welcome to the next

lecture in the computer network series

today we will see the basics of bridge

we will start with outcomes of today's

session in today's session we are going

to understand the basics of bridge we

will know the types of bridges and we

will understand the working of a bridge

and finally we will understand the

difference between a router and a bridge

we will start with the basics of bridge

a bridge it is a repeater

if bridge and repeater are the same then

will do we need 2 different

terminologies and 2 different concepts

and 2 different devices a bridge is

normally a repeater but with some

additional functionalities and the

additional functionality is that it has

the potential of reading MAC addresses

so a bridge is normally a repeater with

the additional functionality of reading

MAC addresses whenever any device that

is dealing something with the MAC

address only then that device will be a

layer 2 device so bridge is also a layer

2 device we will see what is the use of

a bridge bridges are also used for

interconnecting to local area networks

on the same protocol the very important

point is on the same protocol say we

have two local area networks and these

two local area networks are using the

same protocol then bridges are used to

interconnect these two local area

network then it is also a port to device

like a repeater repeater has only two

ports likewise a bridge will also have

only two ports let's have a look at the

types of bridges

there are two types of ridges number one

transferrin bridges and number two

source loading bridges we will see one

by one briefly transparent bridges these

are the bridge in which stations or

nodes are completely unaware of the

brits existence it means in a local area

network is their existing bridge the

stations or nodes are unaware of the

existence of the bridge it means we need

not do any configuration in the stations

in a router we used to give the IP

address of the interface as the default

gateway for all the stations or pcs

whereas in a bridge we need not do that

because the stations are completely

unaware of the brits existence so

reconfiguration of stations is

unnecessary even if the bridge is added

or removed from the network suppose if

we add a bridge or remove a bridge we

need not do any configuration or

reconfiguration in the stations that's

about the transparent bridges

let's now have a look at the second type

of bridge which is the source routing

bridges in source routing bridges the

routing operation is performed by the

source station and the frame specifies

which route to follow for example in a

local area network there is a source

station or a source node if that node is

going to send some data to other node

then this node that is the source

station will have the routing

information how this frame has to reach

the destination so that information is

processed by the source routing bridges

so there are two types of bridges number

one transparent bridges and number two

source routing bridges let's have a look

at the working of the bridge now suppose

if we have a local area network and we

have another local area network to

connect these two local area networks we

bring in a bridge and this bridge

extends the range of the local area

network and interconnects these two

networks that's the working of a bridge

and the very important point to note

about bridge is that this bridge

interconnects two networks that are

running on the same protocols so same

protocol is a very important point to

note here if this is a router router can

interconnect two different local area

networks that need not be the same

protocols they can run two different

protocols now you may have a question in

your mind

if bridge can interconnects to local

area networks router can also

interconnect to local area networks then

what is the difference between a bridge

and a router let's see the difference

between a bridge and a router now the

difference between a bridge and a router

is that a bridge interconnects local

area networks that are running on the

same protocol and the bridge is a layer

2 device that is it processes or it

deals with the MAC addresses whereas if

it is a router then this router

interconnects two different local area

networks that are running with two

different protocols and router is a

layer 3 device so at the basic level

bridges interconnects local area

networks that are running in the same

protocol and it is a layer 2 device it

deals with the MAC addresses only

whereas a router it interconnects two

different local area network that has

two different protocols and router is a

layer 3 device he deals with IP

addresses and a router changes the data

link layer address that is the physical

address or MAC address in a packet and

that's the difference between a bridge

and a router I hope now we understood

the basic of British we know the types

of bridges that is transparent bridges

and source routing bridges we understood

the working of a bridge and we also

understood the difference between a

router and a bridge

I hope the session is informative and

thank you guys for watching

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