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Routing table for management traffic

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  • 1.  Routing table for management traffic

    Posted 10-17-2020 20:31

    Hi, all,

     

    I need help to understand how Junos behaves in this scenario, say I have two loopback addresses, lo0.0 (1.1.1.1/32) and lo0.1(2.2.2.2/32), lo0.0 is in default/master instance, lo0.1 is in its own routing instance, both IP addresses are accessible from a remote management station (say it is a snmp poller with IP address 10.10.10.10), i.e. both instances have valid routing entry for this management station IP. If I ping from 10.10.10.10 to 2.2.2.2, which next-hop (or which routing table) will Junos choose to send echo reply back to 10.10.10.10?

     

    Thanks,



  • 2.  Re: Routing table for management traffic
    Best Answer

    Posted 10-17-2020 23:12

    Hello,

     


    @oldcreek wrote:

    Hi, all,

     

    If I ping from 10.10.10.10 to 2.2.2.2, which next-hop (or which routing table) will Junos choose to send echo reply back to 10.10.10.10?

     


     

    JUNOS will choose the routing table associated with the instance where 2.2.2.2/lo0.1 belongs, or, in other words, where lo0.1 is inserted by means of "routing-instance BLAH interface lo0.1" line.

     

     

    As for the next-hop, it will be determined by the route lookup in this table. If You configured route leaking between instances, it is possible that next-hop will be actually in GRT/inet.0.

     

    HTH

    Thx

    Alex