Glossary
Out-of-Band Management
Out-of-band management is an administrative access path — a separate network, a separate interface, a separate credential — kept distinct from the ordinary path regular users take through a system. The idea is that the interface used to administer a system shouldn't be reachable through the same exposed surface the system's regular traffic uses, so that a compromise of the ordinary user-facing path doesn't automatically hand over administrative control too.
This separation is easy to erode gradually: an administrative feature bolted onto the same public-facing application for convenience, a management endpoint reachable from the same network as regular traffic because standing up a separate one felt like unnecessary overhead at the time. Each shortcut narrows the gap the separation was meant to provide.