Out-of-band (or "OoB") networks are usually dedicated to management tasks. Many security appliances and servers have dedicated management interfaces that are used to set up, control, and monitor the device. A best practice is to connect those management interfaces to a dedicated network that is not directly connected to the network used to carry applications/users' data. If a physically separated network is always best, a dedicated VLAN could do the job in most cases (if properly configured). What we typically find on OoB networks are: