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What is the Native VLAN?

The Native VLAN is an oft confused concept, though it needn’t be. This video will explain what the Native VLAN is and how it affects traffic on a wire.

Summary

An Access port (or “untagged port” in the non Cisco world) is a switch port which carries traffic for only one VLAN.

A Trunk port (or “tagged port” in the non Cisco world) is a switch port which carries traffic for multiple VLANs.

When frames traverse a Trunk port, a  VLAN tag is added to distinguish which frames belong to which VLANs. Access ports do not require a VLAN tag, since all incoming and outgoing frames belong to a single VLAN.

The Native VLAN is simply the one VLAN which traverses a Trunk port without a VLAN tag.

 

Comments

  1. Ashish Mishra says

    Very informative

  2. Dude, this material is absolutely top notch. Colour schemes, explanations!! Congratulations with the material. The ASA NAT article was awesome, full kudos for that.

  3. Absolutely fantastic material with perfect diagram which makes readers eye catching. Worth reading always as expected from you guys. Keep it up

  4. Leonardo Dias says

    Hi Ed,

    As always you do in your articles, it is clear and right to the point.

  5. East or West, Ed Harmoush’s article is always best.

    We all are excited for your next article. After going through your articles we don’t have to look for another to understand the concepts.

    In short I would say “one stop for all networking concepts”.

    Thanks
    Pankaj

  6. One question; what does it mean when the command ‘encapsulation dot1q 1 native’ is used on a trunk port?
    Does it mean tag the native vlan on this trunk? ; or
    Assign vlan 1 as the native vlan on this trunk (untagged, of course)

    I would assume the former, since by default vlan 1 is set the native vlan (on trunk ports)

    • Hi Bogon, encapsulation dot1q 1 native is a Router Sub-Interface command.

      encapsulation dot1q 1 tells the Router which VLAN to associate a particular sub-interface to (i.e., which VLAN to tag and associate incoming / outgoing packets with).

      encapsulation dot1q 1 native tells the Router to associate the sub-interface to VLAN 1, but as the native VLAN — i.e. incoming/outgoing traffic is associated to VLAN 1, but no VLAN tag is added.

      Hope this helps =)

  7. super explanation of VLAN . Kudos to the author.

  8. Ed,
    A great excellent networking learning website. I subscribe it in no time.
    on the subject of VLAN, would you please present a html regarding
    1st) how does management VLAN associate with remote access login(vty line)?..
    2nd) any relationship/what difference between management vlan and native vlan?
    or are they simply totally different subject , nothing related?

    • Hi Ethan. Glad you enjoyed the articles.

      1. The “line vty” configurations simply control how someone can access the device. The IP address someone would use would be in the SVI configuration (i.e., interface vlan #. The VLAN# of the SVI is what determines what VLAN can receive/send management traffic to the switch.

      2. They are different concepts. The VLAN you use for management does not have to be the VLAN you choose not to tag on a trunk port (the Native VLAN).

      Hope this helps.

  9. No doubt ,,, i have gone through no. of things on the internet minimum 700-800 … found this the best for clearing the actual thing what is happening inside the network.

  10. Cannot view your full article even after subscribing…

  11. patrice Bertin says

    Why looking elsewhere? Everything is said so clearly in this site.
    Ed you remind me Keith Bogart……. I mean your explanation are as good as his.

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