So guys, now let us discuss the third benefit which we get from the VLANs.
The third benefit is the restricted flooding of ARP broadcast message.
So restricted flooding means reduced broadcast domain.
So you can see in this topology.
Let us consider the host machine C, which is present in Vlan ten.
Now, if host Machine C issues the ARP broadcast request message to resolve the ARP for IP address of
destination machine D, then this broadcast request message will travel over this link.
Then it will travel over this link and then it will travel over this link.
And finally this hour, broadcast request message will be received by host Machine D.
So you can see that the broadcast domain for host Machine C is shown by the shaded region.
So you can see that the broadcast domain is quite small.
Now let us consider a scenario where l two switches were not Vlan aware.
So you can see on the diagram on the right hand side in this diagram, these l two switches are actually
not Vlan aware.
So if host machine C issues an r broadcast message, that r broadcast message will travel over all the
links of this topology.
So you can see that the shaded region in diagram two shows the broadcast domain for the host machine
C in fact the shaded region in the second diagram is the broadcast domain for all the host machine present
in the topology.
The R broadcast message that is issued or generated by any host machine will going to be received by
all other hosts present in the topology.
So you can see in the second diagram, the broadcast domain is quite wide and big.
So you can see that when l two switches over vlan aware the unnecessary flooding of our broadcast message
was completely prevented, the r broadcast message was not received by any of the host machine which
was present outside the Vlan ten.
In topology one.
So since unnecessary leakage of the traffic is prevented using Vlan aware switches, therefore it also
resolves the security concerns of the network.
So the takeaway from this benefit is that that using the concept of Vlan, the size of the broadcast
domain gets reduced.
You can see you can compare the size of the shaded region between the two diagrams.
And you can easily conclude that the broadcast domain of diagram one is a way smaller than the broadcast
domain of the diagram.
Two.
So this is one of the greatest benefits of VLANs.