Can't add VLAN in the "allowed VLAN"

As an IT administrator, you may find yourself needing to add a VLAN (Virtual Local Area Network) to the allowed VLANs on your network. While adding VLANs can be relatively straightforward, it can also be a difficult task. In this article, we’ll look at some of the common issues you may encounter when adding VLANs to your network and how to resolve them.

The first step in adding a VLAN is to identify the VLAN you wish to add. This can typically be done by using a network device’s management interface or by using a network monitoring tool such as Wireshark. Once you have identified the VLAN to add, you will need to configure the VLAN on the network device. This is typically done by adding the VLAN to the allowed VLANs list on the device and configuring the VLAN’s parameters, such as the IP address range, subnet mask, and VLAN ID.

Once the VLAN is configured, it needs to be added to each port on the network device. This can be done by either manually adding the VLAN to each port or by using a feature such as “Port-Based VLANs”. Port-Based VLANs allows you to configure multiple VLANs on a single port and assign specific VLANs to specific ports.

Once the VLANs have been added to the ports on the network device, you will need to configure the rest of the network. This includes configuring the router to route traffic between the VLANs, configuring the switch to allow traffic between the VLANs, and configuring the firewall to allow traffic between the VLANs.

Another common issue you may encounter when adding VLANs is ensuring that the VLANs are properly secured. This is typically done by configuring access control lists (ACLs) to allow only the necessary traffic between the VLANs. Additionally, you may also want to configure port-security to ensure that only authorized devices can connect to the network.

Finally, you will need to configure the network devices to ensure that the VLANs are functioning properly. This includes configuring the switch to allow traffic to and from the VLANs, configuring the router to route traffic between the VLANs, and configuring the firewall to allow traffic between the VLANs.

In summary, adding VLANs to your network can be a difficult task. However, by following the steps outlined in this article, you should be able to successfully add VLANs to your network. Additionally, you should also ensure that the VLANs are properly secured and that the network devices are properly configured. Doing so will help ensure that the VLANs are functioning as intended.