What Is VLAN (Virtual LAN):If we simply talk about LAN (Local Area Network) then it is to be understood that the purpose of LAN is to connect two nodes with each other and provide direct (layer 2) access to each other.It basically consists of Ethernet switches.IP and router are used for accessing computers on different LAN.
What Is VLAN (Virtual LAN)?
The idea of VLAN(Virtual local area network) is abstracted from LAN but there is some difference between them.A VLAN might have a subset of ports on one switch or on multiple switches.Traffic on one system which is connected to one VLAN cant be seen by other system connected to other VLAN.It is logical subnetwork which partitions the network virtually and groups different physical devices from different physical LANs.
ADVANTAGES OF VLAN
- When a VLAN is correctly setup then it can help to reduce traffic by dividing the network.
- A virtual local area network can combine all the physical device which communicate with each other frequently and split the traffic among them to two or more physical layer.They are handled by its core router.
- VLAN handles traffic by network switches to provide a fast network.
- It provides secure connection and other security benefits for a large network by controlling the device and there access rights to other systems connected to it.
- Many times Wi-Fi guest network is created using wireless access points to implement VLAN.
Types Of VLANs(Static and Dynamic VLAN)
Static VLAN is often offered as “port-based VLANs.”When you use static ports than administrator needs to assign separate ports for each network switch to a virtual network. Even if you add a new device it automatically becomes a member of a pre-assigned group.
Dynamic VLAN allows checking the need of the device first and then provide suitable network membership depending on its characteristic instead of switch port location.
EXAMPLE: To provide a physical address in Dynamic VLAN MAC address can be used or network account names.
VLAN Tagging And Standard VLAN
VLAN tagging uses IEEE 802.1Q industry standard.32 bits (4 bytes) of data is contained in ethernet headers for building 802.1Q tag.0x8100 hardcoded number which forms the first 16 bits of the field.It is used for triggering ethernet and to recognize that the frame belongs to 802.1Q VLAN.VLAN number( from 1 to 4094) is present in the last 12 digits.
There is two other type of VLAN practices which are:
- Native LAN: It is the only VLAN which is not tagged in a trunk.The native frames are transmitted unchanged and are known as VLAN1.
- Management VLAN: On management VLAN it receives only management traffic such as SNMP and it allows to avoid the traffic.
Setting up a VLAN
To set VLAN at a high level:
1.Select a VLAN number.
2.Select a private IP address range for devices on which you want to use the VLAN.
3.Using static or dynamic setting configure the device.A static connection will require the admin to assign numbers to each port and dynamic will require the assignment of MAC address.
4.Configure routing between VLANs as required for communication between two devices.