<Jeremy's IT Lab> Day16: VLANs(Part 1)

VLANs(Part 1)

 

LAN: 

-> group of devices in a single location

-> a single broadcast domain, including all devices in that broadcast domain

 

Broadcast domain:

-> group of devices which will receive a broadcast frame(FFFF.FFFF.FFFF) sent by any one of the members

e.i) group of client with switch, group of VLANs, router to router

 

avoiding unnecessary broadcast traffic in the same LAN

-> configure security policies

>>Although subnet congured but they are still in the same broadcast domain and having the same problem.

 

 

VLANs

-> configured on switches on a per-interface basis

-> logically separate end hosts at Layer 2

-> Switches do not forward traffic directly between hosts in different VLANs

-> The switch doesn't perform inter-VLAN routing. Must send the traffic through the router

Purpose of VLANs:

1. performance

2. security

 

//CLI

SW1#show vlan brief

##VLANs 1,1002-1005 exist by default and cannot be deleted

SW1(config)#interface range g1/0 - 3

SW1(config-if-range)#switchport mode access

SW1(config-if-range)#switchport access vlan 10

## An access port is a switchport which belongs to a single VLAN, and usually connects to end hosts like PCs

## Switchports which carry multiple VLANs are called 'trunk ports'

SW1(config)#vlan 10

SW1(config-vlan)#name ENGINEERING

## Edit the name

SW1(config)#do show vlan brief

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Acronyms:

• VLAN : Virtual Local Area Networks