Virtual Local Area Network – VLAN

A Virtual Local Area Network – VLAN is a logical group of workstations, servers and network devices that appear to be on the same LAN despite their geographical distribution. A VLAN allows a network of computers and users to communicate in a simulated environment as if they exist in a single LAN and are sharing a single broadcast and multicast domain.

VLANs are implemented to achieve scalability, security and ease of network management and can quickly adapt to change in network requirements and relocation of workstations and server nodes.

 

Lets understand it in simple way:-

Suppose you have 2 network in you company 1 is for Staff and one is for Admin and geographically you have 5 rooms to cover so your topology will be like:-VLAN Configurationone network for Admin and one for Staff. So you get 10 switches and if you want to get more network then more switches… But using Virtual LAN you create Virtual LAN in you switch so that you can transmit

 

data of different network throng 1 switch without any collision of broadcast domain.

IF you are using Virtual LAN your topology will become like:-VLAN Configuration

In this case you will create Virtual LAN in your switch. Let see some example of configuration of Virtual LAN

 

Create VLAN:-

You can create VLAN in cisco switches using below commands

Switch>enable

Switch#configure terminal

Switch(config)#vlan 2

Switch(config-vlan)#name Staff

This will create Vlan 2 with name Staff. You can check it using command

Switch#show vlan

It will show you all the Virtual LAN you have. Vlan 1 is default VLAN and all the ports in this vlan by default.

 

Configure Interface for VLAN:-

Their are 2 type of interfaces in switch in terms of Virtual LAN

1.) Access &

2.) Trunk

 

Access:- This type of interface have 1 Virtual LAN and is generally used to connect end devices like servers PC and etc. For more details click here.

Trunk:- This type of interface have multiple Virtual LAN depending upon requirements and is generally used for connection between Switches. For more details click here.

How to configure port in access mode?

Switch(config)#interface f0/1

Switch(config-if)#switchport mode access

Switch(config-if)#switchport access vlan 2

In above command we have configured port as access mode and also have assigned it to VLAN 2.

 

How to configure Port in Trunk Mode:-

Switch(config-if)#interface f0/2

Switch(config-if)#switchport mode trunk

In above commands we have configured port as trunk port. This  will allow all the vlan on this port.

 

You can watch my video on Virtual LAN configuration also. For more Details:-

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