Hello
everyone!
Today, I will start to write about the basic principle of VLAN technology. This is a very important theme in every TCP/IP network, and one of the most important chapters for exam HCIA-Access.
In this article, I will give answers to these two questions: what is VLAN?, and what are the advantages of VLAN technology? Let's get started.
What is VLAN?
VLAN is an abbreviation from Virtual Local Area Network. A VLAN is used to implement many l local networks and to restrict a broadcast domain. VLANs are widely used on L2 networks. Access devices, such as OLTs, run on the L2 TCP/IP model.
Traditional LANs have hosts (PCs, printers, etc.), and they are interconnected by a switch. All these hosts can communicate with each other. The question is what if we want to make two or more local networks. Of course, the simplest solution is the new switches. And the problem is solved. But there are situations when this solution is expensive or even more often not impossible. In these situations, we use a VLAN.
VLAN technology allows us to take one switch (one physical device or one LAN network), and break it up into multiple switches or multiple VLANs (broadcast domains). This way, now, we can fix our network. For example, hosts PC 1 and PC2 belong to VLAN10, hosts PC3, PC 4 and printer belong to VLAN20. After that, only hosts PC3 and PC4 have access to the printer, while hosts PC1 and PC2 do not have that right because they are in VLAN10 - another local network.
What are the advantages of VLAN technology?
This is a very important question. With this answer, we confirm the importance of the existence of VLAN technology.
There are many advantages of VLAN technology:
The broadcast domain is divided, and these new broadcast domains are isolated,
The need to move devices is reduced, e.g. we must not move devices – PCs, servers, printers from one office to another office,
Secure communication is enabled, e.g. only hosts in VLAN100 have access to the base server. All other hosts do not have access to the base server. And if all the hosts are on the same switch, they are not in the same VLAN and this way they are isolated.
If there are problems on the network, they are not transmitted to the whole network. Problems only exist within a single VLAN,
Easier network administration by network administrators. VLAN users can easily change VLAN networks, and they can receive access to certain resources, etc. Of course, there is a possibility of communication between VLANs, but about that in one of the next articles, and etc.
Continued
in the next article >> Basic principles of VLAN technology (2)
Thank you!
