If you've ever managed a Cisco Catalyst 9000 series switch in production, you know that IOS-XE software upgrades are one of those tasks that look simple on paper but can take down a core switch if you get them wrong.

Sarah Chen just published a complete command-by-command guide covering:

• Bundle mode vs. install mode — how to check which you're running and why it matters
• The install add / activate / commit workflow — with real IOS-XE output at each step
• ISSU eligibility — what actually makes an upgrade hitless (and when it isn't)
• 5 common gotchas — flash space, mixed-version stacks, rommon recovery, license issues
• Post-upgrade verification commands — OSPF neighbors, BGP summary, error counters
• Rollback procedures — before and after commit

Read the full guide on ignaonline.com →

— Sarah Chen