During a network outage, I needed to pinpoint where the failure occurred.

Identify the OSI layer causing the issue.

Reviewed each layer—physical cabling, data link switches, network routing, transport protocols, and application services—using appropriate tools (cable testers, ping, traceroute, Wireshark).

Isolated the problem to a faulty switch at the Data Link layer, replaced it, and restored service within 30 minutes.

Designing a video‑streaming service for internal training.

Select the appropriate transport protocol for low‑latency video.

Chose UDP because it offers lower overhead and tolerates occasional packet loss, which is acceptable for streaming. Used TCP for configuration files where reliability is critical.

Achieved smooth video playback with minimal buffering while ensuring critical data transfers remained error‑free.

Tasked with building a LAN for a newly opened branch office.

Create a design that supports current needs and future growth up to 500 users.

Conducted a site survey, defined IP addressing scheme using VLSM, selected core and distribution switches with PoE, implemented VLANs for departments, planned redundant uplinks, documented the design, and presented it to management for approval.

The LAN was deployed on schedule, supported 200 users with 99.9% uptime, and allowed seamless expansion without re‑architecting the core.

Company needed to separate finance, HR, and guest traffic on the same physical infrastructure.

Design and configure VLANs to enforce segmentation and improve security.

Created separate VLAN IDs for each department, configured trunk ports on switches, applied ACLs on the router to restrict inter‑VLAN routing, and documented the VLAN map.

Reduced broadcast domains, improved security by isolating sensitive traffic, and simplified troubleshooting with clear logical separation.

User in the marketing department experienced occasional drops on their desktop.

Identify root cause and restore stable connectivity.

Gathered logs, checked physical cabling, ran ping and traceroute, examined switch port errors, reviewed DHCP lease times, and monitored for wireless interference. Discovered a faulty NIC causing packet loss.

Replaced the NIC, connectivity stabilized, and documented the incident to prevent recurrence.

During a security audit, we discovered several unauthorized APs in the building.

Implement controls to detect and prevent rogue APs.

Enabled WPA3 Enterprise with RADIUS, deployed 802.1X authentication, configured AP whitelisting on the controller, set up continuous wireless intrusion detection (WIDS), and conducted regular site surveys. Trained staff on reporting unknown devices.

No further rogue APs detected for six months, and the wireless network passed the subsequent security audit.

The CFO was concerned about a sudden spike in network latency affecting financial reporting tools.

Explain the cause and remediation plan in business terms.

Used an analogy comparing network traffic to highway congestion, highlighted the specific router bottleneck, presented a cost‑benefit chart for upgrading the device, and outlined the implementation timeline.

The CFO approved the budget, the upgrade was completed, and latency dropped by 40%, improving reporting speed.

A scheduled maintenance window caused an unexpected core switch failure, leading to a 2‑hour outage that I was not on call for.

Mitigate impact, restore service, and prevent recurrence.

Coordinated with the on‑call engineer to expedite failover, communicated status updates to all departments every 15 minutes, performed root‑cause analysis post‑outage, updated the maintenance checklist, and instituted a revised on‑call rotation.

Service was restored within 45 minutes, senior leadership praised the transparent communication, and the new process reduced future outage risk.