job screening question

Diogo Montagner diogo.montagner at
Thu Jul 5 18:20:12 CDT 2012

This type o question where the candidate can elaborate the answer
should be asked by a techinal interviewer.

For screening questions (for 1st level filtering), IMO, the questions
has to be straight to the point, for example:

1) What is the LSA number for an external route in OSPF?

This can have two answer: 5 or 7. So, I will accept if the candidate
answer 5, 7 or 5 and 7. Later on (the next level of the interview), a
techinical interviewer will chech if the candidate understand the
differences of LSA 5 and 7.

The point is that the candidate cannot deviate from the question,
I.e., this question will not generate another question from the
candidate to the interviewer asking for more details about the
scenario in case.

For example, you may ask: which IGP is more reliable under an IP DoS attack?

The answer for this question can be very long or may require some sort
of interaction between the candidate and the interviewer, which means
it has to be asked by techinical people and not by non-techinical


On 7/6/12, William Herrin <bill at> wrote:
> Hi folks,
> I gave my HR folks a screening question to ask candidates for an IP
> expert position. I've gotten some "unexpected" answers, so I want to
> do a sanity check and make sure I'm not asking something unreasonable.
> And by "unexpected" I don't mean naively incorrect answers, I mean
> oh-my-God-how-did-you-get-that-cisco-certification answers.
> The question was:
> You implement a firewall on which you block all ICMP packets. What
> part of the TCP protocol (not IP in general, TCP specifically)
> malfunctions as a result?
> My questions for you are:
> 1. As an expert who follows NANOG, do you know the answer? Or is this
> question too hard?
> 2. Is the question too vague? Is there a clearer way to word it?
> 3. Is there a better screening question I could pass to HR to ask and
> check the candidate's response against the supplied answer?
> Thanks,
> Bill Herrin
> --
> William D. Herrin ................ herrin at  bill at
> 3005 Crane Dr. ...................... Web: <>
> Falls Church, VA 22042-3004

Sent from my mobile device

./diogo -montagner

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