Interview Guide: Network Engineer
- IP Addressing
- Route Filtering
What NOT to ExpectMost interview guides cover questions you’re likely to encounter but it’s also worth talking about once-popular queries that are falling out favor for IT positions, such as:
- Are you a team player? — Softball question and not useful for interviewers since everyone says “yes”. In addition, network engineers must be able to work independently on tight deadlines.
- What’s your biggest weakness? — More of a trap than a question and doesn’t tell the interviewer anything useful.
- Obscure trivia games? — Network design and maintenance is a massive topic and many IT pros have encyclopedic knowledge. The problem? This doesn’t always translate to great hands-on skills.
- What’s a router? Why is it necessary?
Routers are critical to creating secure and efficient networks; of course, you know their value and how to use one! But can you describe it? As IT continues to shift away from break-fix to integral corporate function, technology experts must be able to communicate concepts clearly. So it’s worth the refresher: At their most basic, routers are 3-layer network devices that facilitate inter-network communication via best path selection, packet forwarding, and packet filtering
- Describe the topography of a previous network you worked with. Draw it.
If you’re applying for a network engineer job, you need experience with networks. Even if this wasn’t your previous role make sure you know the ins and outs of the network you most recently worked with. Why? Because the interviewer wants to know if you understand topography, even if you didn’t design it. Be ready to talk about the network setup — and if it wasn’t yours offer some constructive criticism — along with drawing a diagram of the network. Best bet? Practice a few times before you sit down for the interview.
- Detail your troubleshooting process.
What happens when something goes wrong? No network is perfect, and even if your architecture is top-tier it’s impossible to account for everything. While your specific answer will vary, good components include dealing with immediate issues first — outages or hardware failures — then following up with more in-depth analytics.
- Briefly describe the OSI Model
Open System Interconnection (OSI) is an ISO standard which defines seven key layers of networking protocol implementation. Make sure you know the layers and their basic functions:
- Application (Layer 7) — Applications and services including QoS and performance.
- Presentation (Layer 6) — Translation of data from application to network format.
- Session (Layer 5) — Handles connections between applications to improve speed and security.
- Transport (Layer 4) — Transfer of data between systems and error-recovery.
- Network (Layer 3) — Switching and routing technologies to create logical paths.
- Data Link (Layer 2) — Data packets are encoded and decoded to facilitate transportation.
- Physical (Layer 1) — Cables, cards and physical devices necessary to move data through networks.
- How did overcoming a mistake benefit your performance?
This one is a bit tricky — interviewers want to know you can recover from mistakes but also want to make sure you didn’t destroy the network at your last job. Prepare this one in advance — ideally, think of a mistake that wasn’t yours but that you helped correct since this shows you’re both resourceful and capable of handling your new role.
- Why this job?
Critical for senior network engineer positions, companies want to know why you’re interested. While paychecks, hours and benefits are often top-of-mind, enterprises also want someone passionate about the work. Maybe it’s network design itself or troubleshooting critical issues. Maybe you love working with people or changing the perception of IT — whatever the case, make sure you’re prepared to make a case for it in the interview.Get the JobWant to best chance of grabbing that network engineer position? Get back to basics, get on the right path with a certification-driven career guide and get on the shortlist by discovering what to expect during the interview.