What is Out-of-band management?
Out-of-band management uses a different path from the one that carries normal traffic. Examples are a serial console connected to a console server, a baseboard management controller on a server with its own network port, and a separate management network that may have its own internet or cellular link. Because the path is separate, an engineer can reach the device to restart it, change configuration or view the console when the main network has failed.
In-band management uses the production network, so it fails when that network fails. Out-of-band management does not replace on site work, and it does not replace remote hands. It reduces the number of visits, because many faults can be diagnosed and fixed remotely, and it speeds up the visits that are still needed, since the engineer knows what to bring.
Features and names depend on the equipment maker. Security needs care: a management path with high privileges must be kept on an isolated network, with strong authentication and logging. Agree who owns the credentials and who may use them.
How it shows up in practice
- Include the management ports in the cabling plan, and label them clearly. They are easy to forget at install time.
- Test the out-of-band path at install, before it is needed, including login and console access.
- Document where the console servers are, what they connect to, and how to reach them if the main network is down.
- Remote hands requests often start with a console check, so give the provider the console details and the procedure.