Question of the Week 3

Question: Networks Heaven has initially configured all ports of a switch to be the member of VLAN 10. What will be the effect if switch ports are added to a new VLAN i.e., VLAN 12. Options: A.  An addition collision domain will be created. B.  More bandwidth will be required that was needed previously. C.  IP addresses will be wasted by adding a VLAN. D.  An additional broadcast domain will be created.  

Answer to the Question

D.  An additional broadcast domain will be created.  

Number of collision domains = Number of Ports on a switch

Number of Broadcast domains = Number of Vlans on a switch


VLAN stands for Virtual Local Area Network. It is a technology to break down a single broadcast domain into multiple broadcast domains. This technology divides a Physical LAN into more Logical LANs. VLAN technology is used to solve the problem that switches can’t limit broadcast within the LAN. BY default, all ports are member of VLAN 1 and this is the reason that broadcast message will be received and processed by every port.


A VLAN can be thought of as a broadcast domain.  The broadcast or flooded traffic originated from a particular VLAN will be flooded out ports belonging to that VLAN, including trunk ports. This is why hosts within a VLAN normally communicate while communication cannot be achieved between VLANs directly.


Broadcast Domain =  VLAN =  SUBNET