From FreeIPMI's FAQ, http://www.gnu.org/software/freeipmi/freeipmi-faq.html.
Does my system support IPMI?
Unfortunately, there are no universally defined mechanisms for determining
if a system supports IPMI. The following may provide hints.
1) FreeIPMI’s ipmi-locate can be used to determine if IPMI can be found
on your system. Users are cautioned though, the failure to discover IPMI
via ipmi-locate is not sufficient to disprove that IPMI exists on your
system. Your system may not publish such information or may expect
clients to communicate at default locations.
2) dmidecode may be similarly used to probe for devices that support
IPMI on your system. You may grep for IPMI or specifying the IPMI
DMI type on the command line.
# > dmidecode --type 38
# dmidecode 2.10 SMBIOS 2.5 present.
Handle 0x0049, DMI type 38, 18 bytes IPMI Device Information
Interface Type: KCS (Keyboard Control Style)
Specification Version: 2.0
I2C Slave Address: 0x10
NV Storage Device: Not Present
Base Address: 0x0000000000000CA2 (I/O)
Register Spacing: Successive Byte Boundaries
Again, the failure to find an IPMI supported device is not
sufficient to show lack of IPMI support.
Ultimately, some amount of information from product documents
or trial and error may be necessary to determine if IPMI is
supported on your system.