I recently had to write out a list of pro’s and con’s to present to a client who just couldn’t work out why VLANS would work out cheaper than separate physical networks. In doing this i reminded myself that whilst VLANS do give alot more control, there are maybe quite a few situations where seperate physical networks could be more beneficial. It’s not all black and white. Here is the shortened version of the list i came up with:
Pros of using VLANs:
- Flexibility: VLANs allow you to segment your network into different logical networks, which can be useful for separating different types of traffic or users. This can make it easier to manage and secure your network.
- Cost savings: Using VLANs can be more cost-effective than setting up separate physical networks, as you can use a single network infrastructure to support multiple logical networks.
- Simplicity: VLANs can make it easier to manage and troubleshoot your network, as you can isolate different types of traffic and users into different logical networks.
Cons of using VLANs:
- Complexity: VLANs can add complexity to your network, as you need to configure and manage the VLANs themselves.
- Limited scalability: VLANs can be limited in terms of how many devices can be assigned to a single VLAN.
- Performance: VLANs can introduce some overhead and reduce performance compared to using separate physical networks.
Pros of using separate physical networks:
- Simplicity: Using separate physical networks can be simpler to set up and manage than using VLANs.
- Performance: Separate physical networks can offer better performance than VLANs, as there is no overhead introduced by the VLANs.
Cons of using separate physical networks:
- Cost: Setting up separate physical networks can be more expensive than using VLANs, as it requires additional hardware and infrastructure.
- Inflexibility: Separate physical networks offer less flexibility than VLANs, as you cannot easily segment your network into different logical networks.
- Difficulty in managing and troubleshooting: Managing and troubleshooting separate physical networks can be more difficult than using VLANs, as you need to manage multiple physical networks rather than a single network infrastructure with multiple logical networks.
Here are a couple examples, the first is
When Vlans are preferable:
Imagine that you are setting up a network for a large office building with multiple departments. Each department has its own set of servers, workstations, and other network devices, and you want to ensure that the traffic from each department is kept separate from the others.
One option would be to set up separate physical networks for each department. However, this would be costly and inflexible, as it would require setting up separate network infrastructure for each department. Additionally, managing and troubleshooting multiple physical networks would be more complex than managing a single network infrastructure.
Instead, you could use VLANs to segment the network into different logical networks, one for each department. This would allow you to use a single network infrastructure to support multiple logical networks, while still keeping the traffic from each department separate. This would be more cost-effective and flexible than using separate physical networks, and it would be simpler to manage and troubleshoot.
When Separate physical networks are preferable:
Imagine that you are setting up a network for a large warehouse that will be used to store and track inventory. The warehouse will have a large number of sensors, RFID scanners, and other IoT devices that will be sending and receiving large amounts of data.
In this case, using VLANs to segment the network into different logical networks might not be sufficient to handle the large volumes of data being transmitted by the IoT devices. VLANs can introduce some overhead and reduce performance compared to using separate physical networks, so using separate physical networks might be necessary to ensure that the IoT devices have the bandwidth and latency they need.
Additionally, the warehouse network might be too large or complex to manage effectively using VLANs, in which case using separate physical networks might be simpler and more effective.
