Switching

 View Only
last person joined: 20 hours ago 

Ask questions and share experiences about EX and QFX portfolios and all switching solutions across your data center, campus, and branch locations.

Native VLAN, how to recognize if the End-Customer is sending untagged data.

  • 1.  Native VLAN, how to recognize if the End-Customer is sending untagged data.

    Posted 7 days ago
    Edited by Andrei Cebotareanu 6 days ago

    Hello All,

    I am looking to find a solution to a rather "non-trivial" task, same time the issue is very trivial;)))

    I have an EX44k with the Service Provider Style configuration: 

    set interfaces ge-0/0/1 flexible-vlan-tagging
    set interfaces ge-0/0/1 native-vlan-id 2
    set interfaces ge-0/0/1 encapsulation extended-vlan-bridge
    set interfaces ge-0/0/1 unit 1 vlan-id-list 1-4094
    set interfaces ge-0/0/1 unit 1 input-vlan-map push
    set interfaces ge-0/0/1 unit 1 output-vlan-map pop

    This setup will allow my end-customer to send any type of traffic (tagged within the VLAN-ID-LIST range, or untagged - with the help of native-vlan-id).

    All is working perfectly! The task I have is:

    • Using any "non-destructive/service impacting" instruments that are available on EX44k to determine if the customer is sending "tagged" or "untagged" frames
    • If possible to determine the list of VLAN used by the customer (as I have a big vlan-id-list the goal is to know what exact vlans have been used over this interface).

    I can simply ask my end customer, so this is one clear way to achieve the requirements.

    I was looking to use a firewall with the:

    • user-vlan-id 1-4094 - trying to catch any VLANs that are traversing the link.
      • Result: Negative, in some corner cases, this type of FW can not be programmed into HW
    • flexible-match-mask - trying to catch if there is any specific value (0x8100 or IP ether type 0x0800) that can be detected in the L2 frame.
      • Result: Negative, I was unable to find a proper FW setup that will give a clear answer 

    I was curious if anybody could point me in the possible solution direction, or suggest/advise any other ways to achieve my goal.

    Thank you in advance.



    ------------------------------
    Andrei Cebotareanu
    ------------------------------