Friday, January 16, 2015


Introduction of VLAN

          Vlan (Virtual Local Area Network) Foundation:-   Switch Vlan

Ø  Trunk Port :- That Carry All Vlan Traffic Between Your Switches

ü  Logically Groups Users
ü  Segments Broadcast Domain
ü  Subnet Correlation
ü  Access Control
ü  Quality Of Service

v  The Normal Switches World:-
Ø  1 Collision Domain Per Port
Ø  Broadcast Sent To All Ports
Ø  One Subnet Per Lan
Ø  Very Limited Access Control
The Flexibility Of Vlans:-

Ø   Segmentation Of Users Without Routers
Ø  No Longer Limited To Physical Location
Ø  Tighter Control Of Broadcast
 Understanding Trunks and VTP              
    • What is Trunking
    Ø Trunking(also known as Tagging) passes multi-Vlan information b/w switches
    Ø Places Vlan information into each frame
    Ø Layer 2 feature
    Ø Trunking is a Cisco term.

    •    Trunking Language : 802.1Q
    Ø Switches pass the information b/w each other using official languages 802.1Q that is industry standard
  •    Native Vlan:- is designed for packet that received on the trunk that are not tag
  • Double Edge word: VTP 
  • VLAN Trunking Protocol (VTP):-It Replicate the Vlans into Multiple Switches through Trunk Ports

The VTP Modes:-

Ø  Server(Default)
ü  Power to change vlan information
ü  Sends and receive vtp updates
ü  Saves vlan configuration

Ø  Client
ü  Cannot change vlan information
ü  Sends and receive vtp updates
ü  Does not save vlan configuration

Ø  Transparent
ü  Power to change vlan information
ü  Forward (pass through) vtp updates
ü  Does not listen to vtp advertisements
ü  Saves Vlan configuration

  Ø  Off (configurable only in CatOS switches):- in the VTP off mode, switches behave the same as in VTP transparent mode with the exception that VTP advertisements are not forwarded.

Vlan Pruning

Ø  Keeps unnecessary broadcast traffic from crossing trunk link.
Ø  Only work on VTP Server



  1. Please upload PDF of VLAN Introduction

    1. Dear Kindly refer to CCNP Switch option then Vlan and Trunking

  2. Great Article
    Cyber Security Projects

    projects for cse

    Networking Security Projects

    JavaScript Training in Chennai


    Training in Chennai

    The Angular Training covers a wide range of topics including Components, Angular Directives, Angular Services, Pipes, security fundamentals,

    Routing, and Angular programmability. The new Angular TRaining will lay the foundation you need to specialise in Single Page Application developer.

    Angular Training