Junos OS


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Juniper groups

  • 1.  Juniper groups

    Posted 07-27-2021 05:57

    Where can we see the pre-defined groups that Junos recognize ?
    e.g. re0 / re1 / member0 / member1

    What does the "global" group means ?
    e.g. edit groups global

    Does group have precedence over individual statement ?

    Thank you

  • 2.  RE: Juniper groups

    Posted 07-27-2021 19:27
    The names of the groups are like variables, they can be any text desired.  Global is just a default name used in some Junos shipping configurations.

    Groups only apply if they are both created and have the apply-groups stanza added at the correct level in the configuration.  If the group is simply created and NOT applied then nothing happens.

    Individual statements will override the group setting when they are added to a configuration.

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

  • 3.  RE: Juniper groups

    Posted 07-29-2021 09:23
    Hi Steve

    How does Juniper knows member0 actually refers to member ID 0 in a virtual chassis setup ?

    set groups member0 system host-name Switch0​

    When using global name in groups - does it refers to all members in a virtual chassis setup ?

    Thank you

  • 4.  RE: Juniper groups

    Posted 08-07-2021 09:05
    Hi Alan,

    I don't think there is a complete list of the pre-defined groups in Junos, but the ones I know of are:

    re0 (M/MX/EX chassis)
    re1 (M/MX/EX chassis)
    member0..9 (EX/QFX Virtual Chassis)
    node0..1 (SRX)
    sfc0 (TX Matrix platform) 
    sfc0_alt_re (TX Matrix platform) 
    lcc0 (TX Matrix platform) 
    lcc0_alt_re (TX Matrix platform) 
    lcc2 (TX Matrix platform) 
    lcc2_alt_re (TX Matrix platform) 
    lcc4 (TX Matrix platform) 
    lcc4_alt_re (TX Matrix platform) 
    lcc6 (TX Matrix platform) 
    lcc6_alt_re (TX Matrix platform) 
    lcc7 (TX Matrix platform) 
    lcc7_alt_re (TX Matrix platform) 

    These "special" groups will all apply configuration to a specific hardware element in a clustered system.  

    For example, you will most likely want to configure a unique management address on the primary and secondary Routing Engine of a chassis.  Since the interface is named fxp0 on both primary and secondary REs, you would use the groups re0 and re1 to ensure that the IP address is assigned to the correct RE even though the configuration is shared eg:

    set groups re0 interfaces fxp0 unit 0 family inet
    set groups re1 interfaces fxp0 unit 0 family inet
    set apply-groups [re0 re1]

    There is also another pre-defined configuration group named  junos-defaults.
    If you type show configuration groups junos-defaults  Junos will display the hidden default configuration settings for the platform.  
    This is especially useful on SRX where show configuration groups junos-defaults applications will give you good insight into the out-of-the-box application definitions.


    Ben Dale
    JNCIE-SEC #63

  • 5.  RE: Juniper groups

    Posted 08-07-2021 05:28
    The group is just an arbitrary string/name that you, as the administrator, set in order to classify/order the configuration in a better way. Junos does not 'know' where the group is until you as the neteng apply it into the specific hierarchy. For example:

    set groups MPLS protocols mpls interface all
    set protocols mpls apply-groups MPLS​

    In this case, the user-defined group MPLS is defined and apply under the mpls hierarchy, where all interfaces will be MPLS-enabled after this.



  • 6.  RE: Juniper groups

    Posted 08-09-2021 13:21
    bdale is right, and as often the Juniper documentation is missing stuff.

    Additionally, you can have combinations, by example you would use member[0-1]-re[0-1] for MX Virtual-Chassis with double RE:

    For old and obsolete TX Matrix you would have llc[0-3]-re[0-1] too.

    Finally, for Juniper Advanced Insight Solutions / AIS (didn't even knew this): juniper-ais

    And a few reference links, since there's no central doc about this:

    Olivier Benghozi