Network engineer screening questions for recruiters

When you screen a network engineer, you want to hear a sensible troubleshooting order and real changes to routers, switches or firewalls that didn't take anything down. Fifteen to twenty minutes is enough if you ask about specific outages and changes they handled.

What does a network engineer do?

The Bureau of Labor Statistics covers this job on its computer network architects page, which says "computer network architects, or network engineers, design and deploy computer and information networks," including local area networks (LANs), wide area networks (WANs) and intranets. On most teams, the network engineer builds and repairs the connections that let a company's offices, data centers and cloud systems talk to each other. In smaller teams the same person also does the day-to-day upkeep that BLS describes under network and computer systems administrators.

Which skills should you check at each level?

Ask which vendors the client runs. Someone with years on Cisco can learn Juniper or Arista, but some clients want day-one familiarity.

What screening questions should you ask a network engineer?

Swap in the client's vendors where it helps; the order of the troubleshooting steps matters more than the brand.

A user says "the internet is down." How do you troubleshoot it?

The order of their steps tells you more than the steps themselves.

Strong answer: first asks whether it's one user or many, then works up from the connection: cable or Wi-Fi, whether the device got an IP address, whether it can reach the gateway, whether DNS resolves names, then the firewall and the internet provider. They mention ping, traceroute and nslookup.

Weak answer: "Restart the router."

What is a VLAN, and why would you use one?

Strong answer: splits one physical switch into separate logical networks, for example voice, guest Wi-Fi and servers, for security and to limit broadcast traffic. They mention trunk links that carry several VLANs and the router or layer 3 switch needed to move traffic between them.

Weak answer: a one-line definition and no example from their own network.

Which routing protocols have you configured, and in what kind of network?

Strong answer: OSPF inside a company network, BGP to internet providers or the cloud, why each was used, and a problem they fixed, such as two routers that wouldn't form a neighbor relationship.

Weak answer: names protocols but can't describe one setup.

Tell me about a firewall change you made. How did you make sure it didn't break anything?

Strong answer: a change request and maintenance window, a backup of the configuration, a rule as narrow as possible (specific source, destination and port), testing afterward, checking the logs and a rollback plan.

Weak answer: opened the rule to "any" to make it work.

Walk me through the worst network outage you worked on.

Strong answer: a timeline, the root cause (for example a switching loop, a bad routing change or failed hardware), their own role and what changed afterward so it wouldn't repeat.

Weak answer: can't name the root cause, or blames another team and stops there.

Have you automated any network tasks?

Strong answer: describes Python scripts or Ansible playbooks that back up configurations, push changes to many devices or check settings, and how they tested them first.

Weak answer: nothing at all. That's fine for some roles, but not when the job description lists automation.

What cloud networking have you done?

Strong answer: AWS VPCs or Azure virtual networks, subnets, route tables and security groups, and how the cloud connects back to the office or data center over VPN or a private link.

Weak answer: "We moved to the cloud," with no detail on how traffic got there.

What red flags should you note?

• Can't explain what a /24 network means or how subnets work.
• Solves firewall problems by allowing everything.
• Makes production changes without a change window or a rollback plan.
• Lists a CCNA but can't explain basics it covers. Cisco says the CCNA validates "knowledge and skills in network fundamentals and access, IP connectivity, IP services, security fundamentals" and more.
• Has worked only with vendor dashboards for a role that needs hands-on configuration.

Write each one down and test it in your own call. For remote roles, how to spot a proxy interview lists the signs that another person is answering.

How do you run this screen with Simplehire?

Add the client's network skills as the role's required skills, for example routing and switching, OSPF and BGP, firewalls, VPNs and cloud networking, and send the interview link. The candidate talks to our AI interviewer in the browser, and the report is ready before you decide whether to submit them.

On Adaptive, the per-answer assessment lets you read the troubleshooting answer on its own before you look at the verdict and Skills demonstrated X/Y. The decision on the candidate is yours. Each screen runs full-screen, with copy and paste restricted or flagged and tab switches timestamped in the report. Network roles often come with wide access, so for remote contractors we'd add the ID check. A person reviews every alert.

The free tier covers 25 Basic screens a month, no credit card required; see pricing. For related roles, see the cybersecurity analyst, AWS cloud engineer and Azure cloud engineer questions.