WHAT IS VLAN | WHY WE NEED VLAN | CISCO LEYER 2 DEVICE | SWITCH| CCNA | |CCNP | PART 1

ABOUT THIS VIDEO:
TODAY MY TOPIC IS VLAN, AND WHY WE NEED VLAN. VLAN STANDS FOR VIRTUAL LOCAL AREA NETWORK.

A VIRTUAL LAN (VLAN) IS A LOGICAL OVERLAY NETWORK THAT GROUPS TOGETHER A SUBSET OF DEVICES THAT SHARE A PHYSICAL LAN, ISOLATING THE TRAFFIC FOR EACH GROUP. A LAN IS A GROUP OF COMPUTERS CAMPUS — THAT SHARE THE SAME PHYSICAL NETWORK.
VLANS (VIRTUAL LANS) ARE LOGICAL GROUPING OF DEVICES IN THE SAME BROADCAST DOMAIN. VLANS ARE USUALLY CONFIGURED ON SWITCHES BY PLACING SOME INTERFACES INTO ONE BROADCAST DOMAIN AND SOME INTERFACES INTO ANOTHER. EACH VLAN ACTS AS A SUBGROUP OF THE SWITCH PORTS IN AN ETHERNET LAN.

VLANS CAN SPREAD ACROSS MULTIPLE SWITCHES, WITH EACH VLAN BEING TREATED AS ITS OWN SUBNET OR BROADCAST DOMAIN. THIS MEANS THAT FRAMES BROADCASTED ONTO THE NETWORK WILL BE SWITCHED ONLY BETWEEN THE PORTS WITHIN THE SAME VLAN.

A VLAN ACTS LIKE A PHYSICAL LAN, BUT IT ALLOWS HOSTS TO BE GROUPED TOGETHER IN THE SAME BROADCAST DOMAIN EVEN IF THEY ARE NOT CONNECTED TO THE SAME SWITCH. HERE ARE THE MAIN REASONS WHY VLANS ARE USED:

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