VLAN Trunking Protocol ( VTP )

One of the switches is the ability to provide a Virtual LAN ( VLAN ) . It begins with the need for port grouping by function or business needs . Thus the need for a port belonging Engineering , Accounting belonging to another .The reason was that due to flooding . Switch will forward broatcast to all ports . However, by using a VLAN , port group so that we can broadcast from a port in VLAN 1 is only sent to the ports in the VLAN .

 If you imagine a switch or bridge without VLAN capabilities as " Switch stupid " or " basic switch " , then make the same VLAN as smart switches split into several basic switch , which is a virtual switch .Because the broadcast is only passed to the VLAN in question , then we can also assume VLAN as a " broadcast domain " . If you have multiple switches that are connected with a group of ports on each switch , the broadcast domain to include multiple switches are .You may be thinking , " Why do I need a VLAN ? , So what if the accounting view broadcast for part of Engineering ? " The simple answer is security . However , not a lot of traffic passing through the broadcast so it does not matter if someone sees our broadcast . May be more appropriate answer is performance . With VLAN , you separate the groups that share your broadcast on the network .All devices connected to the VLAN receive broadcasts from other members . However , the device is connected to a different VLAN do not receive the same broadcast . VLAN consists of devices communicating as a logical network . In contrast , a physical network consisting of devices that are physically connected by wires .VLAN TrunkWe have seen that VLAN is a broadcast domain , a set of ports or users that we classify. Which may now be the question is, can include multiple VLAN switches ? The answer is yes . This can be done by configuring the VLAN on a switch , with one port per VLAN pairs .Weakness of this method is the number of switch ports that connect the switch . This method is also more manual , takes more time , and difficult to manage . Hence comes the VLAN trunking which aims to connect the switch to interlink ( uplink ) speed , and some VLAV can share a single cable .Trunk links are not made ​​for a specific VLAN . One , several , or all of the active VLANs between switches can be bypassed by using a trunk link . It is possible to connect two switches with separate physical links for each VLAN . However, with the increasing number of VLANs are created , then the number of links can add up quickly . A more efficient way is to use trunking . To distinguish ownership traffic on trunk links , the switch must have a method to identify frames each LAN .VLAN Trunking Protocol ( VTP ) is a Layer 2 feature found on the Cisco Catalyst switch line , which is very useful tertutama switches in large scale environments that include multiple VLANs .