OSPF LSA Type-3 Filtering task

While the solution shows to use prefix-lists and filter lists, would the following be acceptable as a solution?

it does appear to tend the same results.

router ospf 1

 area 0 range not-advertise

 area 3 range not-advertise

 area 3 range not-advertise


  • Based on the wording of the task, I do believe it very well would be just as valid as a filter list. Maybe they should change the wording of the task to steer you in one direction or the other without flat out saying which one to use like the exam does.

  • Hi,

    Your configuration would not accomplish the goal of the task, because the following line of config :

    area 0 range not-advertise

    would prevent R5, as the ABR, from originating the LSA for this specific prefix in any other new area, that would be added later.

    Here is the specific bullet from the workbook :

    • Devices in area 3 do not have reachability information about the
      Loopback0 interface of R1; this should not affect any new areas added to

    Configuration from the workbook denies R1's loopback prefix from entering area 3 and nothing more :

    ip prefix-list R1_LOOPBACK deny
    ip prefix-list R1_LOOPBACK permit le 32

    router ospf 1

    area 3 filter-list prefix R1_LOOPBACK in


    I hope it makes more sense now, good luck !


  • Of course! Thanks for the clarification...


    we should have an ATC on how to read questions properly....

  • I agree on the class on how to read questions! [:D]


    They say there are no "tricks" on the lab, but I find the tricks do exists on how carefully the tasks are worded.

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