Jul 23, 2010

In just seven questions you can narrow down the candidates for that network administrator job to those with true talent and passion.

Interviewing candidates for network administrators is a bit like opening up the door to a herd of Chihuahuas. Sit them down and start talking and all you hear is Yip! Novell? Yip! VPN services? Yip! MCSE? Yip! CCNA? Yip! Yip!

IT managers need to bring on the best talent to run their networks; the company’s infrastructure relies on productive, capable staff. How do you cut through all the Yipping? What questions do you ask to find that stately Shepherd amidst the dog pack?

Whether you are a technical hands-on manager or a business-centric CIO doing that final “check for a fit with the company” job interview, the questions you ask a network admin candidate should check on seven aspects of what makes a good employee: Knowledge, Tinkering, Honesty, Ethics, Community, Discretion, and the all important Sanity Check. We asked network specialists to share their favorite questions (and best answers) to help you eliminate those annoying Yippies.

Knowledge Check: What is a TCP Three-Way Handshake?

Let’s go right for the jugular. By now, you’ve asked a few questions, sniffed through the resume looking for fudged qualifications, determined a level of expertise, and found out how many years she has spent using the technologies on which your organization relies. But do you know what your candidate really knows? Asking a simple question rather than a tough one can be revealing.

Only 5-10% of IT professionals have very strong technical skills, says Robert Brockway, a system and network administrator at a software development company based in Toronto. “I would rather ask them, ‘Describe a three-way handshake.’ That is really an introductory question for a network administrator.”

“Maybe one in 10 people get it right,” he says, “And sometimes these [candidates] are for senior positions.” If someone gets the answer right, Brockway can ask harder questions. “But more often than not, they get that question wrong, and that troubles me,” he says.

The right answer? SYN SYN/ACK ACK. The candidate can go into more detail, Brockway adds, but if the interviewee says that phrase, he gives them high marks. “When you are diagnosing network problems you have to understand the network or you don’t know what you are looking at,” Brockway says.

Tinkerer Check: What is Your Home Network Like?

A good employee manages his own mindset. He has to do what is necessary to keep that elan for the work. A true love of technology helps, especially on the days when you have to slog through one too many worst-case scenarios.

“We’re looking for someone who can bring enthusiasm and curiosity to the office. What we’re looking for the most is someone who has a tinkerer’s mentality. Someone who wants to try out things at home, because they can’t get enough of the technology at work,” says Scott Sherrill, senior systems engineer for the Regional Educational Media Center, a Michigan nonprofit that provides desktop, network, and ISP support for K-12 schools, libraries, and other local agencies.

Perhaps the job candidate is using a wireless server for the family or maybe just trying out cutting-edge technology to see how it goes. Maybe she’s turned an old laptop into a picture frame. Any of those technologies are okay. It’s not necessarily one specific technology that you should look for. It’s more the mindset, says Sherrill.

Of course, this is not to negate a person who has a healthy balance of home life and work; you also want people who don’t invest too much time into their home operation.

However, the answers you get to this question can provide more character insight than the candidate realizes.

“We had a candidate who went on and on about all the pirated software that he had, so right away we had the opportunity to ask: Is this the type of character we want in our organization? He was trying to score points by describing how big his network was and that sort of thing. That this person admitted to something like this in an interview means he is probably not going to be good for us,” says Sherrill.

Honesty Check: What was the Worst Mistake You’ve Made as a Network Administrator?

All thieving aside, a good check of a person’s honesty is finding how easily he will lie to make himself look good.

“I look for a willingness to admit your own faults. Everybody makes mistakes. The key aspect of a mistake is to learn from that mistake. If you’re not willing to say, ‘Here’s what went wrong, here’s what I did,’ then you are never going to learn from what you did,” says David Nolan, a senior network engineer for a midsized global company in the Pittsburgh area. “It’s not about who’s to blame. It’s about how do we avoid this in the future, how do we improve the process, how do we make this better.”

Nolan also presents a list of technologies that his company uses asks the candidate which ones she knows. “If I list 20 technologies and you claim to be experienced with all of them, I’m going to be worried,” says Nolan.

Weeding out the hands-off managers is also key. While the above question is a good indicator, so is asking a candidate to give a detailed description of a project she worked on, from high level to ground work. If the candidate can’t articulate a coherent project vision, you’ve found a superficial show dog whose resume is a waste of ink.

Discretion Check: What was the Worst/Strangest Network You’ve Managed?

In addition to checking whether your candidate can bark out a clear narrative that tells the story behind a beyond-bizarre network and how its oddities were resolved, by asking this question helps you find out if the job candidate will blurt out the secrets of his previous employer.

For example, the job candidate might explain a problem encountered on a network she managed – “how the guys at AT&T had exposed all this iPad stuff” and add, “I told them and told them and they didn’t listen to me.” At one level the candidate is explaining a technical issue. However, “You just told me who your client was, and you just told me what their problem was,” points out Terry Hamilton, president of IASSIST in Toronto. That’s a breach of trust, if not a security issue — and it does not bode well for the candidate’s trustworthiness.

“If someone had relayed that type of information who had worked in a financial institution, or somewhere similar, I would not want them to tell me the organization had (or even perhaps still has) a hole in their network, or had security problems, or had issues with data loss,” he says.

Ethics Check: Do You Belong to LOPSA, SAGE, or USENIX?

People with a code of ethics have given time and thought about the kind of person they want to be. They live according to a set of standards they have given themselves, and no one has asked them to do it. A code of ethics is often something you have to search for and adopt. The League of Professional System Administrators (LOPSA), USENIX (The Advanced Computing Systems Association), and the USENIX special interest group for system administrators known as SAGE all share a code of ethics.

“I always ask if people belong to [these organizations], and people rarely say Yes. It has been my experience that only a small percentage of the people have given any consideration to the ethics of what they are doing,” says Brockway.

“Consider how we use the Internet these days and everything we use it for. The network administrator can spy on your traffic and can do so without anyone knowing, because the network administrator has that privilege and has that knowledge. I’ve come to the conclusion that ethics is extremely important. And that’s one of the reasons why I’m a supporter of these organizations,” he says.

Community Check: Do You Belong to Any User Groups?

If your network administrator doesn’t know that answer to a problem, especially a time-sensitive one, how does he solve it? Does the candidate have a network of peers to turn to, either online or offline? How plugged in is he to technologies that are gaining speed or losing momentum? Who or what is his sources of research and information?

Belonging to a user group, says Brockway, shows that the candidate is interested in technology. “The people who are passionate about something are the best at the subject,” says Brockway.

Sanity Check: If You were a Kitchen Appliance, What Would You Be?

Wisdom, character, honor, integrity, your candidate can have it all. But if they are a whack-a-doodle all that becomes moot. A nut-bar hunt requires drastic measures—even shock and awe tactics. Granted, asking this may backfire and you can lose a good candidate, but you might just be better off without her if she can’t fetch an answer to this question.

There are clear warnings in people’s responses. Electric knives, garbage disposals, bread makers are all cause for alarm. But an interviewee may say he is an oven because he likes to be where the action (and heat) is, or the microwave because he is quick and convenient. Better yet, he might say he is the coffee maker, and as we all know, no office should be without one of those.

However, there is a method to this madness, says Damion Alexander, a system administrator for Bard College in Annandale-on-Hudson, NY.

In addition to checking whether the candidate has a sense of humor, he says, “I want to know if they can think on their feet. Since this question is rarely heard of (so far), it catches people off guard. This gives some measure of how they respond to a situation they’ve never seen or heard before.”

“I rarely measure time [in answering the question], but if they give up easily that doesn’t fare well.  If they give the name of an appliance and can’t come up with at least a basic reason why, then I would worry if they would just spew answers to customers and coworkers with no comprehension of why they were giving that answer,” Alexander says.

“I’ve actually had a CIO candidate refuse to answer the question. Since he had pondered for a while before that, everyone came to the conclusion that he would not do well when things hit the fan.”

The question also shows how a candidate views himself and how he operates, says Alexander.

“For example, we had two candidates for the same position give an answer of dish washer. The first ‘liked to throw everything in and make it clean.’ The second ‘liked to line everything up nice and neat, so that the water reaches every surface, etc.,’” says Alexander.

“The second response, and how he said it, caused some concern because it gave a sense that he preferred a degree of order that our environment just couldn’t provide. Compared to the first who seemed to accept some level of chaos.”

In the end you really have to go with your gut, he says.

What questions would you ask when interviewing a candidate for network administrator? Share your experiences in the comments.

Related Information From Dell.com: Solutions and Services to Maximize IT Efficiency.

[Editor's note: Edited to change the "right answer" for the technical question.--Ed.]

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  • Aug 28, 2010 | CISSP-GUY says:

    What is a TCP Three-Way Handshake?

    It's SYN – SYN/ACK – ACK

    Any good net admin knows this and the really good ones can dissect a packet in their sleep. In hex.

  • Aug 28, 2010 | john says:

    You got the 3-way handshake horrifically wrong. Do you even work in this industry or is that a mega typo?

  • Aug 29, 2010 | TMO says:

    Thank you for your time itexpertvoice.com, we'll let you know if you're a fit for the position…

    *turns to coworker* Seriously? FIN – FIN/ACK – ACK? Get a clue.

  • Aug 29, 2010 | idiot says:

    This is by far the dumbest thing I have ever read.

    If a potential employer asked me what kind of appliance in a kitchen I’d be, I’d literally get up and walk out of the interview.

    This article is a waste of server space.

  • Aug 29, 2010 | Matt Gibson says:

    Hmm. Might want to look at your own answers. The correct three-way TCP handshake is SYN/SYN-ACK/ACK, not FIN/FIN-ACK/ACK.

    Not too professional methinks.

  • The correct answer for a TCP 3 way handshake is not FIN—FIN/ACK—ACK.

    A correct TCP 3 way handshake is:


  • Aug 29, 2010 | Ori says:

    | The right answer? FIN—FIN/ACK—ACK

    Funny because that is wrong my friend. A 3-way handshake is SYN/SYN-ACK/ACK + data and is the procedure to establish a tcp connection.
    What you just described is the 4-way teardown, and it's the procedure to well… tear it down.

  • Aug 29, 2010 | Guest says:

    No such thing as a three-way tcp handshake. It's a four-way handshake, but steps 2 and 3 can and usually are combined to form a three-way handshake. Also it's SYN, not FIN. FIN is used to terminate the connexion.

  • Aug 29, 2010 | Brett Glass says:

    The author clearly isn’t qualified to be a system administrator himself, or he would know that the TCP “three way handshake” is SYN, SYN/ACK, ACK (or usually ACK+DATA). As for kitchen appliances: I’d probably be a Blendtech blender (willitblend.com). Deals with anything.

  • Hi, Brett. Nice to see you again. :-)

    The author (who, ahem, is a she) doesn't claim to be a sysadmin. She interviewed sysadmins, who gave her all these answers and which she compiled.

  • Can she edit the article to stop the pain, then?

  • I can. I'm just waiting on confirmation of the correct info (which should come from the person she quoted, no?) before I do so.

  • Aug 30, 2010 | Brett Glass says:

    Here’s confirmation:





    and more from your favorite search engine.

    Apologies for any confusion as to the gender of the author.

  • I'm the person she quoted. I was alerted to the problem by a member of LOPSA and a correction was sent through.

    I was interviewed over the phone so best guess she thought I said 'FIN' when I said 'SYN'. Some people here would say I have an accent , which may explain it :)

  • Ah. An accent! That explains it. :-)

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