VLAN

                                                           VLAN

Vlan is Broadcaste domain created by Switch.

Data should communicate be same Vlan in switches.

Data should has to communicate different Vlan then its require Layer-3.

It eliminates unnecessary broadcast traffic, improving, performance and scalability.

For Security it’s logically separates users and departments, allowing administrators to implement access-lists to control traffic between VLANs.

It provide flexibility to add and remove the number of host.

                                        

                                           Vlan Range

VLAN 0 & 4095-

These are reserved VLAN which cannot be seen or used.

VLAN 1-

It is the default VLAN of switches.

VLAN 2  to 1001-

 This is a normal VLAN range, we can create, edit and delete these VLAN.

VLAN 1002 to 1005-

 These are use only for fddi and token rings.

Vlan 1006 to 4094- 

This is use for High standard devices extended range of Vlan.

                                          Vlan Port Type

Access port-

It is a member of only a single VLAN & used to connect host devices, such as computers and printers. By default all switch ports are access ports in cisco devices.

Trunk port-

It’s a port which belong to multiple vlan.

                                           Protocol Type

Inter-Switch Link (ISL)-

Its also called as “Double Tagging” & its cisco proprietary.

It encapsulates & Decapsulate on every frame while going across trunk.

It does not understand Native Vlan.

ISL supports upto 1000 Vlans.

DOT1q-

Its IEEE standard- IEEE 802.1q,its also called as “Single Tagging”.

It Tag & Untag the frame while going across trunk.

It can understand Native Vlan.

VLAN can vary from 1 to 4094