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Routing Policy

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  • 1.  Routing Policy

    Posted 03-09-2018 16:11

    Can anyone help me to solve this question?

    policy-options {
    policy-statement example-pol {
    term 1 {
    from {
    protocol static;
    route-filter 10.1.0.0/16 exact;
    }
    then {
    preference 6;
    accept;
    }
    }
    term 2 {
    from {

    protocol static;
    route-filter 10.1.1.0/24 longer;
    }
    then {
    preference 7;
    accept;
    }
    }
    term 3 {
    from {
    protocol static;
    route-filter 10.1.0.0/16 upto /24;
    }
    then {
    preference 8;
    accept;
    }
    }
    term 4 {
    then accept;
    }
    }
    }
    -- Exhibit --
    Referring to the exhibit, if the static route with prefix 10.1.1.0/24 is evaluated against the
    routing policy, which preference value will be set?

    A. The preference will be 6.
    B. The preference will be 7.
    C. The preference will be 8.
    D. The preference will be the default for static routes.



  • 2.  RE: Routing Policy

    Posted 03-09-2018 20:05

    Hi,

    I think it is not matching any of the first 3 terms for subnet 10.1.1.0/24, so it should match term 4 and the preference should remain default of 5 for the static route.

     

    Thanks



  • 3.  RE: Routing Policy

    Posted 03-09-2018 20:44

    Hi Flamengo,

     

    It will match the term 3 and set the preference to 8. Option(C)

     

    Hope this helps

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  • 4.  RE: Routing Policy

    Posted 03-09-2018 23:13

     Can anyone please explain me the use of this policy?

     

    You can't receive the route from protocol static (it's statically configured not advertised or received)

     

    you can't use this policy as an import-policy because we received the route from dynamic protocol not static.

     

    You can apply this policy as an export policy but the preference value is locally significant so no use of "then preference" statement

     

    You can apply this policy in "instance-import"  but "from instance <instance name>" statement is missing. without which this policy will not work.

     

     

    It could be a childish question but I am curious to know.

     

     

     

    Is there any other use of this policy? 



  • 5.  RE: Routing Policy

    Posted 03-10-2018 16:20

     Hi VVadivel,

    The prefix 10.1.1.0/24 is into the filter 10.1.0.0/16 upto / 24 . 

    So the answer c is correct?



  • 6.  RE: Routing Policy
    Best Answer

    Posted 03-10-2018 18:41

    Hi Flamengo,

     

    yes your understanding is correct

     

    Hope this helps

    --------------------------------------------------------------------------------------------------------
    If this post was helpful, please mark this post as an "Accepted Solution".
    Kudos are always appreciated!
    --------------------------------------------------------------------------------------------------------