White Paper - Remote Management SNMP SubAgent

Exhibit 2: SNMP Message Format
3. Baseboard Management Controller
Intelligent Platform Management Interface (IPMI) defines a standardized, abstracted, message-based
interface to server management hardware [4]. The key characteristics of IPMI for inventory,
monitoring, logging and recovery control functions are available independent of the main processors,
BIOS and operating system. These functions can also be made available when the system is in a
powered down state; however system should be connected to AC power and network. This interface
is exposed through standard management interfaces such as SNMP, CIM, WMI, etc. The heart of the
IPMI architecture is a microcontroller that is Baseboard Management Controller (BMC). BMC contains a
firmware that manages the interface between system management software and the platform
management hardware. The key functions provided by this interface are SEL (System Event Log), SDR
(Sensor Data Record) repository, PEF (Platform Event Filtering), etc. The complete management
interface and functions of BMC are mentioned in the IPMI specification [6].
4. System Event Log
BMC provides a centralized, non-volatile SEL and adds event messages to it. These messages can be
significant or critical management events raised by the management controllers. Event receiver
writes message into the SEL. Each SEL entry has a unique ID field that can be used for retrieving it.
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