Why Use VLANs
There are many reasons why organizations opt for VLANs over Local Area Networks (LANs) and Wide Area Networks (WANs) including cost-effectiveness, productivity in the administrative workforce, scalability, security, and flexibility in network management.
Types Of VLANs
There are three types of VLANs including Port-Based VLANs, Mac-Based VLANs, and Protocol-Based VLANs.
Port-Based VLANs
This VLAN type groups virtual local networks based on ports. Switch ports in this case are configured manually to member VLANs. Devices connected to this port exist in similar broadcast domains. The main challenge of this network type is that it can be difficult to know which ports are good for each VLAN.
MAC-Based VLANs
MAC Based VLANs work by allowing incoming untagged packets to be assigned to virtual LANS hence classifying traffic based on packet source address.
Protocol-Based VLANs
As the name suggests, this kind of VLAN operates by using traffic-based protocols to filter criteria tags that take the shape of untagged packets.
How VLAN Works
Switches are the most important components for the functioning of VLANs. They perform critical functions such as acting as entry points for end-station devices into the switched fabric, thereby facilitating the flow of information in the entire organization. They also provide intelligence to ports, group users, or logical addresses into communities sharing common interests.
Each switch is designed to make filtering and forwarding decisions by frame, depending on VLAN metrics set up by network engineers, and to forward this information to other networking devices such as routers in the network. Frame tagging is the criteria used in the logical grouping of nodes into a VLAN.
That said, VLANs are identified by numbers, so the first task is to assign relevant VLAN numbers (1-4094) on the VLAN switch. The switch then facilitates communication between several ports. A simple trick to connect two or several switches in an organization is to assign a port on each switch with a VLAN, then run a cable between them.
VLAN Characteristics
- Broadcast domain size-reduction
- Device management and administration tasks are made easier
- Reduced latency and Improved performance
- Hosts can be kept separated in a VLAN
- Reduction of physical devices in a network topology
- VLANs solve broadcast challenges
- VLANs offer scalability for growing organizations
- Enhancement of network security
- Physical boundary removal