Do you have to allow the native VLAN?
The one big reason to not include the native VLAN is the list of allowed VLANs is that a native VLAN is a security risk. The current best practice is to not include the native VLAN in the allowed VLANs on a trunk, and to not use VLAN 1 for anything. There is a misconception that you must have a native VLAN on a trunk.
How is the native VLAN secure in a network?
In Cisco LAN switch environments the native VLAN is typically untagged on 802.1Q trunk ports. This can lead to a security vulnerability in your network environment. Many organizations use network enclaves to separate their network to help prevent against threats in one domain from spreading to another.
Why is it important to define a native VLAN?
If the native VLAN is configured wrongly for the trunk ports on the same trunk link, layer2 loops can occur. When it is configured to 802.1Q on a cisco switch, then it is possible to define a different native VLAN. We can access VLAN to an access port from that defined native VLAN which is for an operational trunk.
Do You need A native VLAN for Trunk ports?
1 Answer 1. You can and most likely will need to use a native VLAN on your trunk ports, at least on Cisco switches, other vendors do it differently. But what you have to remember that the security risk is more to do with VLAN 1 (default VLAN) being set as a native VLAN.
Why are switch ports assigned to a VLAN1?
All switch ports are by default assigned to a VLAN1. To ensure better security by keeping the host that works with sensitive data on separate VLAN. Finally, we can conclude that the basic purpose of native VLAN is to serve it as a common identifier on opposing ends of a trunk link.
Why is VLAN 1 not used for control plane traffic?
Although VLAN 1 user traffic can be pruned from a trunk, it is not the case with control plane traffic.” – editorials.org. Since the Native Vlan is used for untagged frame, having all unused ports in Vlan1 makes it possible for anyone to plug in a device on any of those ports and be able to eavesdrop on frames that are sent between Vlans.