Difference Between Subnet and VLAN



Whether you want to learn CCENT, CCNA, or Network, understand the subnets, and VLAN context is essential. At first, it was hard to tell the difference between a subnet and VLAN( virtual LAN). At first glance, they all involve creating segments or partitions of existing networks.

But that's more than that. After further study, you will find that there is not much in common between them.


To understand the differences, you need to have a basic understanding of the data link layer (layer 2) and the network layer (layer 3). In this article, we will discuss the actual meaning of subnet and VLAN and their differences.

OSI Model Layers

Let's briefly introduce the OSI model before discussing the VLAN or subnet. Open system interconnection (OSI) is a model to conceptualize the model of computing functions. This is a 7-tier model used as a tool to track data flows on a network.

  • Application Layer (Layer 7)
  • Presentation Layer (Layer 6)
  • Session Layer (Layer 5)
  • Transport Layer (Layer 4)
  • Network Layer (Layer 3)
  • Data Link Layer (Layer 2)

Physical Layer (Layer 1)

The model is usually decomposed according to the protocol used for communication. Layer 1(as its name implies) is the physical level at which data processing begins. Layer 7(application layer) is the top level of communication between protocols such as telnet and Http. All other transactions from starting a data request to accessing the internet are between these two layers.


VLANs Work on Layer 2


A VLAN works at the info link layer or layer 2. briefly, VLAN isolates the network and create discrete broadcast domains. VLAN should be easy enough to conceptualize if you are satisfied with the concept of LAN( LAN). If not, then Jeremy Joyara (Jeremy Cioara) will allow you to be blinded.


A "regular" LAN is a way of grouping device physics together. VLAN is a method of grouping devices into one or more logically isolated networks. And it's important to note that there can be multiple VLANs. On the same switch, instead, you can make one VLAN across various switches.


The only way to isolate the network before VLAN is to have two complete sets of devices (i.e., routers, switches, and nodes). To set the appropriate LAN by VLAN, you can now use a single switch to create multiple logical networks without having to own a switch for each LAN.


Pro Tip: To route traffic between VLAN, you need a layer three routing device. This is a standard stumbling block for beginners. Simply because two VLANs are located on the same switch does not mean they can communicate.


Use Cases for VLANs

One of the main reasons you might focus on VLAN is increased security. Equipment in different VLANs can not communicate with each other. You can create a VLAN for the visitor network while keeping the company reset within a secure distance. And you can even go further by creating multiple VLANs. for all your departments


Suppose you want all accounting departments to have access to the same information. You can put them all on the VLAN1 to prevent anyone not on this Subnet from viewing traffic. You can repeat this for any other department within the company and create VLAN2 or VLAN3.


In addition to the increased security, it also helps to improve network speed. VLAN will help them communicate and exchange information faster without having to follow regular network traffic.


Since VLAN can not exchange information from different VLANs, they can not cope with conventional traffic patterns. We use standard traffic mode to help in this visual effect. In this example, we will use the 2-lane highway. If trucks and cars use both lanes at the same time, then no matter which path you use, traffic will arrive at the same time.


The problem is that the truck (in this example, the larger packet) will travel at a slower speed. Now, we will call it the left lane VLAN1 and the right lane VLAN2. VLAN2 only allows trucks to pass through, and cannot switch to VLAN1.


This will enable VLAN1 to move at a constant speed to clear network traffic. If a single department like the accounting department we mentioned earlier has been connected to VLAN 1, they can move back and forth without having to fall into regular traffic.

You can do all of these without using a dedicated switch for each LAN. This allows someone on the 10th floor and the 1st floor to be in the same VLAN.

Subnets Work on Layer 3


The Subnets work on the IP or 3rd layer of the OSI model. Subnets enable you to create smaller networks in more extensive overall networks.

Standard IPv4 addresses are usually divided into network ID and host ID. The first two segments are network ID(172.16); the other two sections are host ID(1.10). If we adopt B class 172.16.1.10 when requesting information to the internet, it will first pass to the network and then move to the host using the host ID. These numbers are unique in every system. A portion of the host ID is used to identify the Subnet where the host locates when creating a subnet. In the same example,1 in 172.16.1.1 identifies the Subnet.

Use Cases for Subnets

Because each Subnet can only use a certain number of IP addresses, splitting it into multiple subnets will control the number of partitions. This allows you to manage better how to handle network growth.


By reducing the number of hosts on this Subnet, will also increase your network speed. In this way, you can increase processing speed by reducing the number of hosts on the Subnet when requests enter.


The most important reason to study multiple subnets is probably security. By dividing the network into multiple subnets, you can better monitor traffic to identify threats with faster response times.


However, since it is located in Layer 3, traffic can be seen by anyone who has direct access to the switch you are connected to. This means that you need to take some precautions at level 2.

Learning to Subnet Manually

If you're about to take the online authentication exam, it's essential to know how to do IPv4 subnet partitioning manually. At a high level, there are three key points IPv4 understanding subnet partitioning:


Knowledge of binary mathematics. Zero-sum may be confusing at first, but as time goes by, they become meaningful.


understanding CIDR notation. /24=255.255.255.0, but why? This is the use of binary mathematics. In binary,255.255.255.0 is 11111111.111111111111111.00000000(twenty-four leading figures). The use of "/" followed by numbers is called CIDR( non-classed interdomain routing) notation, which is very common in IPv4 networks.


Practice, practice, practice. The more subnets you do, the better you get. Practice until you can shake the Subnet. There are many applications and online tools that can test your skills and take advantage of them.

Wrapping Up

VLAN work at the ethernet level (layer 2) and the Subnet at the IP level (layer 3). it is essential to remember this distinction to avoid configuration errors and security negligence. VLAN adds communication between devices on the LAN by making them look permanently physically connected.


A subnet will create multiple hosts to limit the quantity of knowledge routed thereto host while allowing you to organize for potential growth. As mentioned earlier, the number of IP addresses you have in any subnet is limited. Generally, there are 1 VLAN to 1 subnet, providing you with two layers of security.

Comments:


Start the discussion...


To Leave a Comment or reply to posts please log in