A native VLAN is a VLAN without a tag. By default, VLAN1 is active on switches, and since it is tagless, two computers between two switches can communicate without any processing.
What is Native VLAN?
The ports configured as trunk connection can pass 802.1Q and ISL tags. However, if no Trunk connection is configured between the two Switches, only computers on the Native VLAN (VLAN1) can communicate.
The reason we make trunk connection between two switches is that the access ports cannot pass tags.
How Does It Work?
The native VLAN is unaffected and can successfully pass frame packets between the two Switches. Therefore, VLAN1 enabled by default on Switches.
Since VLAN1 is untagged, any computer or device connected to the Switch can communicate without being a member of a VLAN. However, it cannot communicate with other devices that are members of the VLAN.
For inter-VLAN data flow, the Inter-VLAN operation performs on the routers. If Layer 3 Switches are available in a network environment, VLAN routing can perform with these devices.
The use of VLAN1 is not recommended for network security. Therefore, it is strongly recommended that you change VLAN1 for your network security.
Now, let’s take a look at the network topology in the image below and examine the operating logic of VLAN1.
Pinging between VLAN1 member PCs will be successful. However, ping between VLAN5 member PCs will fail.
Also, a VLAN1 member computer will not be able to communicate with a VLAN5 member computer!
VLAN1 Working Principle ⇒ Video
Using Packet Tracer, you can watch the video below to examine the operating logic of VLAN1 between two Cisco Switches and also subscribe to our YouTube channel to support us!
In this article, we have examined what VLAN1 is and how it works by default when configuring VLANs in Switches. Thanks for following us!
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