IPMI - technical background

IPMI and “in band” and “out of band” management

In the field of system management, a distinction is made between “in-band” and “out-of-band” management:

The term “in-band” management is used when the operating system is running on the managed server.

The term “out-of-band” management is used when the operating system is not running on the managed server, for instance if the hardware is faulty.

As different interfaces are available in an environment with IPMI compatible systems, you can manage IPMI compatible systems either “in band” or “out of band”.

IPMI-over-LAN

“IPMI-over-LAN” is the current name for the specification of the LAN interface in the IPMI standard. This specification stipulates how IPMI messages can be sent to or from the BMC of a managed system - encapsulated in RMCP (Remote Management Control Protocol) data packets. These RMCP data packets are transferred via an Ethernet LAN connection using the UDP (User Datagram Protocol) under IPv4 (Internet Protocol Version 4).

The RMCP protocol has been specified to support the management of system statuses in which the operating system is not running. The RMCP is a simple inquiry/response protocol.

The interface for such a connection is provided on an onboard LAN controller assigned to the BMC.

IThe interface can only be provided by an on-board LAN controller, not by an inserted LAN card.

26

iRMC S2/S3

Page 26
Image 26
Fujitsu IRMC S2/S3 manual IPMI-over-LAN