Infrastructure

In the source example, the primary changes to 127.0.0.3 at serial 10 while the secondary remains at 127.0.0.2. Raising serial to 11 lets the secondary acquire the changed address.

Zone transfer copies authoritative data under explicit authorization and serial rules

AXFR transfers a complete DNS zone so another server or authorized client can obtain its data. A secondary can then answer authoritatively from its local copy. The protocol does not magically identify callers as legitimate authoritative servers: access control decides who may transfer. A zone is also a defined authority boundary, not every record in every delegated child zone or the organization’s entire DNS namespace. ...

An unrecorded rename proposes destroy plus create; a compatible moved mapping carries the same identity from old to new.

Infrastructure as code is a changelog, not magic

Declarative infrastructure describes a desired result and lets a tool calculate changes. An imperative script can also inspect existing resources and behave idempotently; duplication is not inherent to scripting. Terraform’s advantage is a shared model of configuration, resource identities, dependencies, and proposed actions that reviewers can inspect together. ...