Configure IP Address to VLAN Interface of Switch

What is VLAN?

VLAN (Virtual Local Area Network) is a sub-divided virtual interfaces of Local Area Network (LAN). VLAN's are used to overcome the broadcast and collision domains by dividing the single LAN in sub Virtual LANs'. VLAN's are also used for optimization of network performance.

Switches

Switch is also like HUB but it is also an intelligent device. It is also use on Physical Layer of OSI model which is used to connect multiple end devices to create a local area network. Switch works on the basis of MAC-Address Table which it maintains in its memory. In this table switch stores the MAC-Address of device and port number on which that end device is connected.

When switch receives a packets it first of all matches the source and destination MAC-Address written in packet header with the table which maintained by switch. If source and destination MAC-Address matches with the table entries then switch sends that packet to the destination but if address doesn't match then switch holds the packet and first sends a broadcast message to all the devices to update its MAC table.

Switches also have ability to control the collision and broadcast domains.

Advantages of VLANs

• Increased Performance: Switches by nature increase the performance of network over shared devices which are used today by reducing the collisions. By creating VLANs which means grouping useres into logical network increases the performance of network by limiting the broadcast traffic to useres of the same group.
• Improved Management: Virtual Local Area Networks (VLANs) provide easy, flexible and cheap way to modify the logical groups while changing the environments. VLANs make easy to manage larger networks by allowing centralized configuration of devices located in same network.
• Simplification of Software Configurations: Virtual Local Area Network allows the administrator to manage the network by grouping of users. Software Configurations are made easy and same across the whole network under same subnet.
• Security Option Increases: Virtual Local Area Network (VLANs) have the ability of additional security which is not available at shared network. Switch delivers packet only to the end device whoes IP Address is mentioned on the packet header.

Disadvantages of VLANs

• Limitations in Device: Each device can only support 500 Ethernet address which is distribution of 20 devices per port of a 25 port switch. In ideal networks, only one device is connected with one port at a time.
• Constraints of Port: When hub and switch are connected with one port then every port of that hub will belong to the same VLAN. Hub does not have the ability to provide individual VLANs to the ports and VLANs can’t be extended beyond the ports of device even that switch is able to support VLANs that are attached.

Configurations

Switch>enable
Switch#configure terminal
Switch(config)#hostname TestSwitch
TestSwitch(config)#enable password cisco (Plain Text Password)
TestSwitch(config)#enable secret class (Enycrpted Password)
TestSwitch(config)#line console 0
TestSwitch(config-line)#password cisco
TestSwitch(config-line)#login
TestSwitch(config-line)#exit
TestSwitch(config)#line vty 0 15
TestSwitch(config-line)#password cisco
TestSwitch(config-line)#login
TestSwitch(config-line)#exit
TestSwitch(config)#interface vlan 1
TestSwitch(config-if)#ip address 192.168.1.1 255.255.255.0
TestSwitch(config-if)#no shutdown
TestSwitch(config-if)#exit
TestSwitch(config)#exit
TestSwitch#copy running-config startup-config