What is the difference between in-band and out-band hardware monitoring?

In-band monitoring

Out-band monitoring

Entuity v19.0 supports both in-band and out-band server hardware monitoring. Please see below for a summary of each kind of monitoring.

In-band monitoring:

In-band monitoring consists of an application running on the main server itself, via an SNMP agent on the main interface. This means that if the interface goes down then there will be no SNMP data from it. However, in-band monitoring has an advantage in that both software and hardware can be monitored from a single IP, therefore only costing a single license. With in-band monitoring of server hardware, you can click a link from the Key Info dashlet that takes you through to the OS monitoring associated with the selected server hardware, which is not possible with out-band monitoring.

Out-band monitoring:

Out-band monitoring consists of a separate microcontroller on the server, and so is a separate network interface. Often it will be plugged into a different switch and network to the main network. This can be used to reboot, reset or configure the server even if the main server is off. Out of band monitoring therefore means you are not using the main OS or interface to manage the server.

An example of out-band monitoring is HP Proliant iLO. It is discovered independently from its interfaces, not on the same IP, and is not automatically associated together.