3.13. THE PEF TABLE AND SNMP TRAPS
Channel Authentication The PEF Table and SNMP
Many IPMI systems can specify that certain operations be done when an event comes in. This can depend on the event’s contents; different actions can be done for different sets of events. This is done with the Platform Event Filter (PEF) configuration. Not all IPMI systems can do event filtering, but ones that do will work as this section describes.
The PEF configuration allows several different actions to be perform when an IPMI event comes in (or when the BMC powers up and there are pending events in its event queue). Except for sending an alert, if multiple event filters match, the higher priority action will be done and the lower priority action will be ignores. The actions are:
power down power cycle reset Diagnostic Interrupt
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(optional) Power the system down. (optional) Power off the system, then power it back on. (mandatory) Reset the main processor in the system. (optional) Send a system-defined diagnostic interrupt to the main processor in the system. This is generall an NMI. Send an alert of some type, via an SNMP trap, a page, or a modem dialup. Note that unlike the rest of the actions, this action will still be done if a higher priority action is done. Alerts can also be prioritized via the Alert Policy Table as described in section 3.13.3.
(optional) Priority is defined by the OEM.
This sections will mainly focus on sending SNMP traps with alerts, although the other parts will also be covered. The PEF configuration can specify sending SNMP traps to inform the the management system that something has happened. Generally, it is saying that an event has been placed into the event log. Most of the event information is in the SNMP trap, but unfortunately, some key information is not there. It does give the system an immediate notification.
To have a system send traps, two tables must be set up. The LAN configuration table described in section 3.9.1 has parameters to set the SNMP community string and the trap destination addresses available. The PEF table contains information about how to filter traps. Different events can cause different traps to be sent to different places. As well, specific events can do other things, such as reset or power off the system. The thing we are interested in is the “Alert” capability.
Note that alerts can also cause telephone pages, serial dialups and things like that to happen. They are pretty flexible, although this section will mostly focus on SNMP traps.
These commands control the PEF and alerting capabilities of a system. Table 3.32 shows the command used to find out what alert capabilities a BMC has.
Request - Response 0