VLAN is a custom network which is created from one or more local area networks. It enables a group of devices available in multiple networks to be combined into one logical network. The result becomes a virtual LAN that is administered like a physical LAN. The full form of VLAN is defined as Virtual Local Area Network. Show The below topology depicts a network having all hosts inside the same virtual LAN: network having all hosts inside the same VLANWithout VLANs, a broadcast sent from a host can easily reach all network devices. Each and every device will process broadcast received frames. It can increase the CPU overhead on each device and reduce the overall network security. In case if you place interfaces on both switches into separate VLAN, a broadcast from host A can reach only devices available inside the same VLAN. Hosts of VLANs will not even be aware that the communication took place. This is shown in the below picture: VLAN in networking is a virtual extension of LAN. A LAN is a group of computer and peripheral devices which are connected in a limited area such as school, laboratory, home, and office building. It is a widely useful network for sharing resources like files, printers, games, and other applications. In this Virtual LAN tutorial, you will learn: How VLAN worksHere is step by step details of how VLAN works:
VLAN RangesHere are the important ranges of VLAN:
Example of VLANIn the below example, there are 6 hosts on 6 switches having different VLANs. You need 6 ports to connect switches together. It means, if you have 24 various VLANs, you will have only 24 hosts on 45 port switches. Example of VLANCharacteristics of VLANHere are the important characteristics of VLAN:
Types of VLANsHere are the important types of VLANs Types of VLANPort-Based VLANPort-based VLANs groups virtual local area network by port. In this type of virtual LAN, a switch port can be configured manually to a member of VLAN. Devices that are connected to this port will belong to the same broadcast domain that is because all other ports are configured with a similar VLAN number. The challenge of this type of network is to know which ports are appropriate to each VLAN. The VLAN membership can’t be known just by looking at the physical port of a switch. You can determine it by checking the configuration information. Protocol Based VLANThis type of VLAN processes traffic based on a protocol that can be used to define filtering criteria for tags, which are untagged packets. In this Virtual Local Area Network, the layer-3 protocol is carried by the frame to determine VLAN membership. It works in multi-protocol environments. This method is not practical in a predominately IP based network. MAC Based VLANMAC Based VLAN allows incoming untagged packets to be assigned virtual LAN and, thereby, classify traffic depending on the packet source address. You define a Mac address to VLAN mapping by configuring mapping the entry in MAC to the VLAN table. This entry is specified using source Mac address proper VLAN ID. The configurations of tables are shared among all device ports. Difference between LAN and VLANHere is an important difference between LAN and VLAN:
Advantages of VLANHere are the important pros/benefits of VLAN:
Disadvantages of VLANHere are the important cons/ drawbacks of VLAN:
Application/Purpose of VLANHere are the important uses of VLAN:
Summary:
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