You try and be as diligent as possible, ask as many tough questions as you can, and yet, you realize after hiring that the new-hire isn’t quite as good at the practical hands-on portion of the job as you had hoped. This is a pretty common story in this industry that has it’s hiring process centered largely around putting our trust in industry certifications.

The unfortunate part of a lot of certification exams is that they don’t always test real-world scenarios as much as we’d hope. This is why I believe the industry should be incorporating interview labs more often.

The first time I came across this was my interview for Duke University and I thought it was brilliant. This isn’t some CCIE-level, crazy difficult lab. It was a simple set of common scenarios that you’re likely to encounter daily but that would require that you have at least more than a beginner's level of experience.

The lab that I had to complete had a trunking issue, a VLAN issue, an IP addressing issue, an OSPF configuration task, and a simple BGP configuration task. The whole lab was open-book as it was meant to be as real-world as possible. You have access to Google in you’re day-to-day job and if you need it to complete the task then you’re welcome to use it. What I found later on in doing this same lab for future candidates is that if you need to rely on Google to figure out most of the issues, you’re never going to finish in a reasonable amount of time.

Speaking of time, we usually gave candidates about an hour to complete all of the tasks. The BGP configuration task was more of a bonus question and usually wouldn’t disqualify a candidate if they couldn’t get through it in time.

The beauty of the lab is that there’s usually no single correct fix and the candidate isn’t usually restricted in their solution. If moving a cable fixes the trunking issue, then by all means do it.

After being on the interviewer side of this lab for many years, I found out how many seemingly competent candidates it weeded out.

So, how can you run a similar lab for your interviews? I’ve put together a Git repository that contains configurations that you can run in EVE-NG as well as a set of scenarios for the candidate. You should be able to modify the configs for Cisco CML-2 or GNS3 if you’re more familiar with them.

I estimate that most mid to senior-level engineers should be able to complete the lab in under an hour.

https://github.com/arharris2/NetworkingInterviewLab

If you have questions or horror stories from interviews, I’d love to hear them in the comments!