Career Development
Mock Interview
Questions they actually ask. Two sets of answers.
Q1. Explain the difference between distance vector and link state routing protocols.
What they want to hear
Distance vector protocols share routing tables with neighbors periodically. Link state protocols like OSPF flood LSAs to build a complete topology map and run SPF to compute best paths.
What you're thinking
One of them caused an outage last Tuesday. I'm not saying which. I'm saying it wasn't link state.
Q2. A 10G link shows 40% utilization but users are reporting latency. What do you investigate?
What they want to hear
Interface errors, QoS policy, buffer utilization, microbursts, application-layer issues, and end-to-end path analysis.
What you're thinking
Have you tried blaming the app team? No? Let's start there.
Q3. Design a highly available data center network with sub-second failover.
What they want to hear
ECMP, OSPF as underlay IGP, VXLAN/EVPN for overlay, anycast gateways, BFD for fast failure detection, dual redundant spines.
What you're thinking
Budget?
Q4. How do you handle a P1 incident at 3am when the team is unreachable?
What they want to hear
Follow the incident runbook. Escalate through the on-call chain. Document all actions in real time. Send status updates every 15 minutes.
What you're thinking
Ah yes, the runbook. Written in 2019. Links to a wiki that no longer exists. Step 3 references a tool we decommissioned. I'll follow it carefully.
Q5. What is your experience with network automation and SDN?
What they want to hear
Ansible, Terraform, Python scripting, NETCONF/YANG, OpenFlow, controller-based architectures, CI/CD pipelines for network configuration.
What you're thinking
I have attended every SDN webinar since 2016. The future of networking has been arriving for 10 years now. I remain optimistic.
Q6. Where do you see yourself in five years?
What they want to hear
In a senior or principal engineering role, contributing to architecture decisions, mentoring junior engineers, and growing with the organization.
What you're thinking
Somewhere with a change freeze and a coffee machine that works. Ideally not on-call. This is non-negotiable.
good luck · the real answer is always DNS · don't say that