ipmitool talks to a server's baseboard management controller (BMC) via IPMI: power control, sensor readings, hardware event log, and console access, even when the OS is down.
Local (on the server itself)¶
sudo modprobe ipmi_si ipmi_devintf # load drivers (usually automatic)
sudo ipmitool sensor # temperatures, fans, voltages
sudo ipmitool sel list # system event log
sudo ipmitool chassis status
sudo ipmitool lan print 1 # BMC network settings
Remote¶
ipmitool -I lanplus -H bmc.example.com -U admin -P '<password>' chassis power status
ipmitool -I lanplus -H bmc.example.com -U admin -E chassis power cycle # -E reads password from IPMI_PASSWORD
ipmitool -I lanplus -H bmc.example.com -U admin -E sol activate # serial-over-LAN console (exit with ~.)
ipmitool -I lanplus -H bmc.example.com -U admin -E chassis bootdev pxe # next boot from network
Use -E (environment variable) or -f passwordfile instead of -P, so the password does not appear in ps output or shell history. Treat BMC interfaces as high-risk: place them on an isolated management network, change default credentials, and disable IPMI-over-LAN if unused. IPMI 2.0 has protocol weaknesses. Prefer vendor tools (racadm for Dell) or Redfish where available.