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Vlan, not irb

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  • 1.  Vlan, not irb

    Posted 08-08-2020 16:33
    I'm not up to speed on why exactly juniper has turned to the irb rather than the vlan object. At least that's what I'm seeing I think. My srx300 has an irb. My srx240b2 has the vlan. My question is this.

    Does any of the srx 300 series sport a vlan object? If not, why, not.

  • 2.  RE: Vlan, not irb

    Posted 08-08-2020 18:03



    Greetings, you are seeing this difference because the SRX300 uses the enhanced layer 2 software and you SRX240 does not 


    ELS devices use the "IRB interface" as the SVI, here is a list of devices that are ELS as well, any other device that is not in this list will be considered as a legacy device hence they will use the "vlan interface" as their SVI


    Junos OS 15.1X49-D40
    Junos OS 15.1X49-D40
    Junos OS 15.1X49-D40
    Junos OS 15.1X49-D40
    Junos OS 20.1R1
    SRX550 HM
    Junos OS 15.1X49-D40
    Junos OS 15.1X49-D65
    Junos OS 15.1X49-D65
    Junos OS 17.4R2
    Junos OS 15.1X49-D10
    Junos OS 15.1X49-D10

    If this solves your problem, please mark this post as "Accepted Solution" so we can help others too \:)/




    Lil Dexx JNCIE-ENT#863, 3X JNCIP-[SP-ENT-DC], 4X JNCIA [cloud-DevOps-Junos-Design], Champions Ingenius, SSYB



  • 3.  RE: Vlan, not irb
    Best Answer

    Posted 08-08-2020 18:10

    Hello Eugene,


    All the legacy SRX series devices with the Junos code 12.3X48 and below uses VLAN interface while the Next-Generation SRX series devices with Junos code 15.1X49 and above uses IRB interfaces. However, for QFX/EX/MX IRB interfaces was introduced way before these Junos versions.


    The reason for introducing this IRB interfaces replacing the VLAN is given in the following link -


    Excerpt from the above link:

    In 2013, Juniper introduced a new configuration syntax for EX switches (starting with Junos 13.2) to remedy this: Enhanced Layer-2 Software (ELS). This syntax is similar to the syntax used on MX routers. One of the changes in the new syntax is renaming vlan interfaces from vlan.xx to irb.xx. You can find a complete list of all changes on the website.