How Does Router Handle Different Vlans?


When you need to set up a new network, one of the first things you need to do is assign addresses to devices on that network. This process is usually done using a router. As routers become more and more complex, it can be difficult to understand how they work and what options are available to you. In this blog post, we will take a look at how routers handle different vlans and what this means for you as an user.

What is a VLAN?

A VLAN is a Layer 2 network device setting that specifies how devices on the same physical segment are treated as if they were on different subnets. Devices on different VLANs cannot communicate with each other, even if they are on the same network. Routers manage traffic in accordance with VLAN assignments.

How Router Handles Different Vlans?

Routers use a variety of methods to determine which VLAN traffic is allowed to pass through it. The three main methods are:

  1. Strict VLANs-Routers that support strict VLANs will only allow traffic on specific VLANs to pass through them. Traffic that is not on the specified VLAN will be blocked.
  2. Port-based VLANs-Routers with port-based VLAN support will allow traffic from any source on any destination on the same physical port to pass through without restriction, as long as the destination is Member of the same vlan as the source.
  3. Multiple vlans-When a router has multiple vlans configured, it will use a combination of these methods to determine which traffic is allowed to reach its ultimate destination.

How to Configure Router for Different VLANs?

How to Configure Router for Different VLANs?

When configuring routers, it is important to understand how they handle different VLANs. Routers use a Layer 3 switching model and can support up to 64 logical interfaces. When a router is configured with multiple VLANs, each interface will be assigned to a specific VLAN. The router will then provide routing between the different VLANs.

To configure a router for different VLANs, follow these steps:
The first step is to create the desired number of logical interfaces on the router. For this example, we will create three logical interfaces on the router and assign them to respective VLANs.

Once you have created the desired number of logical interfaces, you need to assign each one to a specific VLAN. To do this, open the configuration menu of your router and navigate to Interface Configuration > Ethernet/WAN Interface > IP Addresses & Subnetting (or similar title). In this screen shot, we have assigned interface 2 (eth2) in Vlan 2 and interface 1 (eth1) in Vlan 1:

Now that eth2 has been assigned to Vlan 2 and eth1 has been assigned to Vlan 1, our routers can route traffic between these two distinct LAN networks:

Difference between VLAN and Trunking

The process of assigning a VLAN to a port on a router is slightly different than the process of assigning a trunk to an interface. With VLANs, each port on the router can be assigned its own VLAN number. This means that each port can be isolated from other ports on the router and from other routers on the network. Trunks, however, allow network traffic to flow between different switches over a single physical connection. Traffic in one VLAN is able to travel across the trunk and into another VLAN without having to pass through any other ports on the router or switches.

VLANs are often used when there are separate networks within a single organization, such as departments within a company. For example, employees working in marketing may have their own network, while those working in sales may have their own network. The departmental networks could be separate from the corporate network or they could share some common resources, such as servers. Trunking allows all traffic between these networks to flow freely without having to go through any routers or servers between them.

How to Enable/Disable a VLAN on Your Router?

How to Enable or Disable a VLAN on Your Router By default, routers will create VLANs as needed.

To enable or disable a VLAN on your router, follow these steps:

  1. Open the router’s administrative web page.
  2. In the navigation bar at the top of the page, click Wireless and Networking.
  3. In the left column of the Wireless and Networking page, click LAN Control and then VLANs.
  4. In the right column of the LAN Control and VLANs page, under Enable/Disable VLANs, select one of the following options:
    • Enabled: The selected VLAN is enabled and operational.
    • Disabled: The selected VLAN is disabled and not operational.

Pros and Cons of Using Router for Networking

Pros and Cons of Using Router for Networking
routers are often used in place of other networking devices, such as switches, to allow for more flexibility and control when setting up a network. Routers can be connected directly to networks, or they can act as a bridge between two networks. Routers also have the ability to handle multiple vlans simultaneously.

One advantage of using routers for networking is that they are more versatile than other devices. For example, a router can be connected directly to an Ethernet network, which allows it to handle all traffic on that network. A switch, on the other hand, would need to be connected to both an Ethernet network and another network (for example, a wireless network) in order to handle different types of traffic. Additionally, routers can often be configured to act as DHCP servers or DNS servers. This means that they will automatically assign IP addresses and manage domain name services (DNS).

However, not all routers are created equal. Some routers only support certain types of ports and protocols (for example, 802.1q). Additionally, some routers may not be able to handle multiple vlans simultaneously. Finally, some routers may have lower performance when compared with other networking devices.

What are the benefits of using a VLAN?

A VLAN is a layer 2 network segment that allows devices on the same physical network to share common resources, such as broadcast and multicast traffic. This can reduce congestion and improve the performance of individual devices on the network.

VLANs can also be used to group together different types of devices, such as servers, printers, and storage devices. This allows administrators to manage these devices more easily and centrally. Additionally, VLANs can be used to isolate networks from each other. For example, a corporate network could be divided into two VLANs: one for employees and one for customers. Devices on either VLAN would not be able to access devices on the other VLAN.


Router handles different vlans in a manner that is transparent to the switch and router. The router learns the traffic patterns on which it will be operating, then sets up its routing accordingly. This way, all the routers connected to the switch are handling traffic in a consistent manner, regardless of what VLAN they are assigned to.

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