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Virtual-Switching EX4200

  • 1.  Virtual-Switching EX4200

    Posted 08-19-2021 21:06
    Hi Guys

    This is my first time configuring the Juniper, but I have a question related to virtual switching.
    1. What are vlan.0 and vlan.1 in the show interface terse vlan output?
    2. I can delete these vlans 0 and 1 and leave just vlan (default)?

    I appreciate who can help me.


    Thiago Morais

  • 2.  RE: Virtual-Switching EX4200

    Posted 08-23-2021 06:05
    The interfaces vlan.0 and vlan.1 are the layer three interfaces for that associated vlan.  If you don't need these to be on the Junos device then you can delete them.

    The vlan stanza declares the properties of the layer two which includes the vlan number and associated interfaces including which layer 3 interface is in that vlan.  So you would need to delete the vlan.0/vlan.1 here too.  But leave all the interfaces you want to stay in the layer 2 vlan.

    In Junos default is just a name so this can be used, changed or deleted as desired and does not have to remain as is.  The vlan id can change or any of the interfaces layer2 or 3.  This is just in some factory configurations as a convenience.

    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)

  • 3.  RE: Virtual-Switching EX4200

    Posted 08-23-2021 19:56
    Hi Steve
    Thank you for answering my question.

    My lab has two EX4200 switches configured in the virtual chassis scenario, when I check the configuration (show virtual-chassis status), I see both switches in the output, when I check the interfaces (show interfaces terse), I see a little difference between interface from unit0 to unit1. In the unit0's interfaces, I see the physical port and logical identifier, for example, ge-0/0/1 and ge-0/0/1.0 eth-switch. This "0" corresponds to unit0 right? Why I didn't see the same output for the interfaces in unit1? The unit1's interfaces are only showing the ge-1/0/1 (not the eth-switch).

    When I need to configure a VLAN in the interface, I am always using the unit0 in the set interfaces ge-1/0/1 unit 0 family ethernet-switching vlans members vlan100 command, this is the right way to do that?


    Thiago Morais

  • 4.  RE: Virtual-Switching EX4200

    Posted 08-24-2021 06:04
    The unit is the number after the period and has to be configured before it will show up in the view.
    First letters are the physical type of interface
    First number is the fpc slot - in a virtual chassis each switch is assigned a number here so the first number is the specific switch
    Second number is the pic - this is a logical grouping based on the chip set used in the device.  For most ex switches there is one for the bulk of the ports and addition fpc for addin ports used generally for uplinks.  These generally indicate the shared fabric of the ports.
    Third number is the actual port number.
    The number after the period is your configured unit number.

    More details are in this documentation.

    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)

  • 5.  RE: Virtual-Switching EX4200

    Posted 08-24-2021 09:31
    Thanks Steve.

    To configure the interfaces during the set interfaces ge-X/X/X unit X... command, which value I must use in the unit parameter 0 or 1? I must use the specific unit value (fpc) based on the unit number?

    set interfaces ge-0/0/1 unit 0 family ethernet-switching ...
    set interfaces ge-1/0/1 unit 1 family ethernet-switching ...

    I am concerned if one of the units fails if the L3 interface will keep up and running in the other unit.

    Thiago Morais