Junos OS

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  • 1.  How to distinguish physical interfaces and logical interfaces

    Posted 04-25-2014 07:46

    Hi Expert,

     

        I read the massge from http://forums.juniper.net/t5/Junos/Juniper-logical-interface-concept/m-p/163660#M6567 to know what's the purpose of logical interfaces in Juniper devices. Here I have a quick question: Can we distinguish physical interfaces and logical interfaces based on the format of interface name? For example:

     

    If the interface is a physical interface: the format should be something like: <interface type>-1/1/0

    If the interface is a logical interface: the format should be something liek: <interface type>-1/1/0.xxx, xxx might represent a logical unit identifier.

     

    If yes, is it a standard judgement method?

     

    Thanks~



  • 2.  RE: How to distinguish physical interfaces and logical interfaces

     
    Posted 04-25-2014 07:52

    Yes your understanding is correct, XXX is the logical unit number.

     

    Regards,

    Raveen



  • 3.  RE: How to distinguish physical interfaces and logical interfaces
    Best Answer

    Posted 04-25-2014 07:55

    Yes the Junos interface naming convention is very standardized as follows:

     

    XX-99/99/99.999 

     

    The values to the left of the period represent the physical interface name, where XX is the interface type:

     

    ge, xe, vlan, etc . . . 

     

    and 99/99/99 represent the line card / interface card / port # 

     

    Then the value(s) to the right of the period represent the naming of the logical interface:

     

    .0 is a standard (non vlan) based logical IF for ge, xe, fe, etc. 

    .999 could be a vlan IF or some other type of logical IF.

     

    You can configure / access the logical I/F's by using either of the two conventions 

     

    user@host# set interfaces xx-99/99/99.999  . . . . 

    or

    user@host# set interfaces xx-99/99/99 unit 999  . . . .

     

    Hope this provides you with your answer. 



  • 4.  RE: How to distinguish physical interfaces and logical interfaces

    Posted 04-25-2014 08:14

    Many thanks for your quick and professional answers:)