Network documentation fails because it is written once, as a project deliverable, and then diverges from reality within a quarter. This template is scoped to the things that change slowly and are expensive to rediscover at 02:00.
Certificate expiry is the most predictable outage there is, and it still happens constantly, usually on an internal service nobody realised had a certificate at all. This tracker covers those as deliberately as the public ones.
Firewall rule bases grow and never shrink, because adding a rule solves a problem today and removing one might cause an outage tomorrow. This log makes removal safe by requiring evidence of use before a rule is retired.
IP conflicts are almost always an administrative failure rather than a technical one: two people assigned the same address because neither had a single place to look. This sheet is that place.
The risk in decommissioning is rarely the shutdown; it is the dependency nobody knew about and the data nobody checked for. This checklist front-loads both, and ends with the licence and backup cleanup that pays for the exercise.
Servers built ad hoc are the ones missing from monitoring and backup, discovered during an incident or an audit. This checklist exists so that every build ends in the same known state regardless of who did it.
Network hardware fails quietly into unsupportability: firmware stops receiving security updates, support contracts lapse, and the vendor announced end-of-life two years ago. This inventory surfaces those dates before they become an incident.
DNS accumulates records faster than anyone removes them, and a CNAME pointing at a decommissioned cloud resource is a subdomain takeover waiting to be found by someone else. This inventory makes stale records visible.