Subnets vs VLANs. A VLAN is a layer 2 term, usually referring to a broadcast domain. Layer 2 is where MAC addresses are used. A subnet is a layer 3 term.
Layer 3 is the IP layer where IP addresses as used. Although one can have more than one subnet or address range per VLAN, it is recommended that VLANs and Subnets are 1 to 1. In general, we will have a 1:1 mapping of subnets and VLANs i.e. One subnet per VLAN.
VLAN stands for Virtual Local Area networks and they are defined by 802.1q protocol (it’s a VLAN tagging protocol that allows the ethernet frame size to increase by four bytes due to the insertion of a four-byte VLAN tag into the ethernet frame). Using VLANs we can virtually separate our LANs into smaller networks, they work like normal LANs except they are logically or virtually separated as opposed to physically.
There are a few reasons to use VLANs, one of the main reasons is to broadcast traffic. VLANs give us all of the benefits of physically separating our network virtually without spending extra money on hardware. The traffic still behaves in the same way as if it was physically separated or split.
Benefits of VLAN –
- VLANs make it easier to split a single switched network to match the security and functional requirements of the system without making any drastic changes in the network infrastructure.
- With VLANs, we can set up Multiple Virtual networks on one physical port and on Wi-Fi.
- They are also important because they help in improving the overall performance of a network by grouping the most frequently communicating devices together.
- VLAN reduces the broadcast traffic and also makes it very easy to control broadcast domains.
- It makes Network administration easy.
- Increases security.
Subnet/subnetwork is a network inside a network or it’s a smaller section (subnetwork) of a large network. Basically, subnets are a logical partition of an IP network into several smaller networks for making the network fast and efficient.
Benefits of Subnets –
- Subnetting divides broadcast domain i.e., improves the speed, efficiency, and network performance.
- Reallocating IP addresses
- Reduce network congestion
- Improve network security
Difference between VLAN and Subnet :
| S.NO | VLAN | Subnet |
|---|---|---|
| 1. | VLAN is a virtual or logical LAN its purpose is to communicate with other devices within the same LAN. | A subnet is a logical partition of an IP network or it’s an IP address range of IP addresses and it helps hosts to communicate over layer 3 (Network Layer). |
| 2. | It allows us to create different physical and logical addresses. | It allows us to create logical networks within the same physical network. |
| 3. | VLAN is configured at the switch side i.e. if you have the switch you can decide which ethernet port is assigned to which VLAN. | A subnet is decided by the IP address. |
| 4. | As VLAN is based on MAC address hence it’s a Layer 2 (Data link layer) term. | A subnet is based on an IP layer hence it’s a Layer 3 (Network layer) term. |
| 5. | VLANs provide better and more stable network access. | Where as Subnet has limited control. |
| 6. | VLAN is primarily software-based. | A subnet is more hardware-based. |
