Calmly Assess the Situation:- Lets take pause to avoid compounding issues or understand correct situation. Communicated clear impact to stakeholders about situation and expected delay. Try to isolate problem :- possibly try to isolate problem, hardware, software, network etc,,, using logs or monitoring tools. narrow down to specific hardware/area. validate upgrade configuration :- validate situation and if required rollback upgrade. check configuration pre-post changes. Pre-requisites for upgrade. perform basics testing. If required need to involve principle vendor or escalation. implement solution gradually. Once problem resolved need to document lesson learn.

Challenges during a network upgrade to stay on track: • We document everything: We maintain detailed change logs for troubleshooting and future reference. • Problem isolation: We break the problem into smaller parts to quickly identify the root cause. • Leverage expertise: We don't hesitate to involve vendor support or specialized professionals.

To troubleshoot unexpected network upgrade issues, I would first document the problem and assess its scope, identifying affected devices and services. Then, I'd verify configurations against the upgrade plan and check logs for errors. Next, I’d isolate the issue by testing individual components, starting with basic connectivity using tools like ping and traceroute. I'd prioritize critical services, rollback changes if necessary, and escalate to senior team members or vendor support if unresolved. Communication with stakeholders and maintaining a detailed incident log ensures transparency and future prevention, while applying patches or fixes as needed to restore full functionality.

To troubleshoot unexpected issues during a network upgrade, start by staying calm and acting methodically. Identify the affected areas and users, then review recent changes—problems often stem from small overlooked details, like VLAN configurations or firewall rules. Check device logs for clues, and if the issue is critical, don’t hesitate to roll back to a stable version while investigating. Test fixes step by step, confirming they resolve the issue without introducing new problems. Keep everyone informed about the progress and next steps. Finally, document the cause, actions taken, and lessons learned to improve future upgrades. Staying organized is key—there’s always a solution!

A detailed, well-designed upgrade plan should cover most of the common issues that impact this type of activity. It requires knowledge of the environment and technologies involved, and previous experience with such migrations. - Perform a complete assessment of the HW and SW to be affected. - Read all available documentation - upgrade, deployment, configuration, installation and troubleshooting guides, SW release notes, data sheets, compatibility matrices, etc. - Prepare a detailed step-by-step plan, including a playbook and a runbook. - Build a detailed workflow with all the possible tasks, tests and checkpoints. - Define an activity window with at least 50% of time for possible troubleshooting and rollback. Murphy is King, not God!