Playbooks
Working a problem in the right order
Individual checks are in the tool reference. These are the sequences — what to run first, what each answer eliminates, and where people usually waste the first hour.
- Making a DNS Change Without Causing an Outage Lower the TTL days ahead, verify against resolvers rather than your own cache, and know what you will do if it goes wrong before you press save.
- Certificate Expiry: Building a Process That Does Not Fail Automated renewal removes the routine work and leaves a new failure mode: a process that has quietly stopped. Verification is what closes it.
- Email Deliverability Triage "Our email is going to spam" is a symptom with at least four unrelated causes. Working them in the right order saves days.
- Is It Down, Or Is It Just Me? Most outage reports arrive as one data point. Turning that into a location takes four or five checks, in a specific order.
- What Are We Actually Exposing? Nobody deliberately exposes a management port. Exposure is what is left over after two years of changes nobody documented.
- Reading a Traceroute Without Fooling Yourself A hop showing 100% loss is usually fine. A hop where latency rises and stays risen is usually not. Telling them apart is most of the skill.