10 VLAN Numbering Best Practices

VLANs (Virtual Local Area Networks) are a great way to segment a network into smaller, more manageable pieces. VLANs are used to separate different types of traffic, such as guest traffic, corporate traffic, and IoT traffic.

When configuring VLANs, it is important to follow best practices for VLAN numbering. This will help ensure that the VLANs are configured correctly and that the network is secure. In this article, we will discuss 10 VLAN numbering best practices that you should follow when configuring VLANs.

1. Use a numbering scheme

A numbering scheme helps you to easily identify the purpose of each VLAN. For example, if you have a VLAN for your finance department, it would make sense to assign it a number like “100” or “200” so that it is easy to remember and recognize.

Using a numbering scheme also makes it easier to troubleshoot any issues that may arise with your network. If you know which VLANs are associated with certain departments or services, then you can quickly narrow down where the issue might be coming from. This saves time and resources in the long run.

2. Keep the number of VLANs manageable

When you have too many VLANs, it can be difficult to keep track of them all. This can lead to confusion and mistakes when configuring the network. It also makes troubleshooting more difficult because there are so many different VLANs that need to be checked.

To avoid this problem, try to limit the number of VLANs in your network. If possible, use a numbering scheme that allows for easy identification of each VLAN. For example, if you’re using a /24 subnet mask, you could assign VLAN numbers from 1-255. That way, you’ll know which VLAN is associated with which IP address range.

3. Create separate voice and data VLANs

Voice VLANs are used to carry voice traffic, such as VoIP calls. Data VLANs are used for all other types of data traffic, such as web browsing and file transfers. By separating the two types of traffic into different VLANs, you can ensure that your network is optimized for both voice and data applications.

Additionally, by creating separate voice and data VLANs, you can also improve security on your network. For example, if a malicious user were to gain access to your data VLAN, they would not be able to access any of your voice traffic. This helps protect sensitive information from being compromised.

4. Don’t use VLAN 1

VLAN 1 is the default VLAN on most switches, and it’s also used for management traffic. This means that if someone were to gain access to your network through VLAN 1, they would have access to all of your data.

To avoid this security risk, you should always use a different VLAN number for each of your networks. You can assign any number between 2-4094 as long as it isn’t already in use. Additionally, it’s best practice to keep your numbering scheme consistent across all of your switches so that it’s easier to manage.

5. Assign VLAN numbers that are easy to remember

When you’re troubleshooting a network issue, it’s important to be able to quickly identify which VLANs are associated with which devices. If your VLAN numbers are easy to remember, then it will be much easier for you to diagnose and fix any issues that arise.

For example, if you have three different departments in your organization, you could assign each department its own VLAN number: 10 for the sales team, 20 for the marketing team, and 30 for the IT team. This way, when you need to look up information about a particular device or user, you can easily recall which VLAN they belong to.

6. Reserve VLANs for future use

When you’re setting up a VLAN, it’s important to make sure that the numbers you assign are unique and don’t overlap with any other VLANs. This is especially true if you plan on expanding your network in the future. By reserving certain VLAN numbers for future use, you can ensure that there won’t be any conflicts when new VLANs are added.

It’s also important to document which VLANs have been reserved so that everyone involved knows what numbers should not be used. This will help prevent confusion and mistakes down the line.

7. Consider using private VLANs

Private VLANs are a type of VLAN that can be used to segment traffic within the same broadcast domain. This is especially useful for organizations with multiple departments or teams, as it allows them to keep their data separate and secure from one another.

Private VLANs also help reduce network congestion by isolating certain types of traffic, such as voice or video, onto dedicated VLANs. This helps ensure that these types of traffic don’t interfere with other types of traffic on the network.

Finally, private VLANs make it easier to manage large networks because they allow administrators to assign specific VLAN numbers to different departments or teams. This makes it much easier to identify which devices belong to which team or department, making troubleshooting and maintenance much simpler.

8. Avoid overlapping IP subnets

When two VLANs have overlapping IP subnets, it can cause a number of issues. For example, if one device is connected to both VLANs, the device will not be able to communicate with other devices in either VLAN because the same IP address exists on both networks.

To avoid this issue, make sure that each VLAN has its own unique IP subnet. This means that all devices within a single VLAN should use the same IP subnet and no other VLAN should use the same IP subnet. Additionally, you should also ensure that your VLAN numbering scheme follows a logical pattern so that it’s easy to remember which VLANs are associated with which IP subnets.

9. Be careful when changing VLAN IDs

When you change a VLAN ID, it can cause disruption to the network. This is because when a device sends out a broadcast packet, it will be sent to all devices in that particular VLAN. If the VLAN ID has changed, then the broadcast packet may not reach its intended destination.

Therefore, it’s important to plan ahead and make sure that any changes to VLAN IDs are done carefully and with minimal disruption. It’s also important to document any changes made so that they can be easily tracked and reversed if necessary.

10. Document your VLAN configuration

When you have multiple VLANs, it’s easy to forget which one is used for what purpose. Without documentation, troubleshooting can become a nightmare as you try to figure out why certain devices are not communicating with each other.

Documenting your VLAN configuration helps ensure that everyone in the organization knows exactly how the network is set up and configured. This makes it easier to identify problems quickly and resolve them without having to spend time trying to figure out what’s going on.