CCIE Pursuit Blog

March 9, 2009

Open Ended Question of the Day: 09 March 2009

What mechanism does the ‘ip ospf flood-reduction’ command utilize to suppress the ‘paranoid refresh’ in a stable network?

Highlight for answer: It sets the DoNotAge bit.



  1. There’s no way a question like that can appear at the lab right?

    They’re supposed to be general and easy?

    Comment by kikimonster — March 9, 2009 @ 3:08 pm | Reply

  2. Haha, either I’m having a bad morning or that was a major reality check…maybe no CCIE for me in 2009.

    Comment by lowjo — March 9, 2009 @ 3:12 pm | Reply

  3. Well I remembered that LSAs did not get aged when configuring flood reduction, but then Ive configured this command before. You will also see DNA next to the entry for the LSAs generated by the router that was configured with this command.
    Kikimonster at the end of the day Id say its better to be overprepared than not. By being overprepared for the theory this will make life easier for the lab portion as well.
    So I’d recommend reading through the command references, and trying to get familiar with what commands are available and what they do…
    I think the way the question was worded (paranoid refresh) may have thrown some ppl off perhaps.
    Its worrying when u even hear that some ppl who thought the open ended questions were easy still did not pass them.

    Daily open ended questions like this (and IEs own application when it comes out), will be good revision for us all.

    Cheers pursuit

    Comment by routeleaker — March 10, 2009 @ 12:20 am | Reply

  4. I believe the router uses psychoanalysis to suppress the refreshing of paranoia.

    Comment by Jeff Rensink — March 10, 2009 @ 7:01 am | Reply

  5. @ Jeff Rensink – “I believe the router uses psychoanalysis to suppress the refreshing of paranoia.” LOL!

    Comment by cciepursuit — March 11, 2009 @ 9:21 am | Reply

  6. @kikimonster – These are just some questions that I threw together after reading the Cisco OSPF documentation. I haven’t seen any of the actual Core Knowledge questions (I hope to only see 4 of them ever – on my next lab attempt 🙂 ) so I’m not sure if this would be something that Cisco would consider for a Core Knowledge question.

    Comment by cciepursuit — March 11, 2009 @ 9:26 am | Reply

  7. the answer may the “ISPF”?

    Comment by yuan — March 23, 2009 @ 8:15 am | Reply

  8. Kills the 60 min auto flood of the network, aka DNA as mentioned above.

    Comment by ryan — April 2, 2009 @ 6:47 pm | Reply

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