Configuration of HP ILO can be done using reboot of your HP server and Press <F8> to configure the ILO settings but you need a down time to your ESXi host and all the virtual machines running on it if it is a standalone host and no option to vMotion to other host. It is really a tough task to get downtime for your virtuali machines just for your ILO configurations like Reset ILO configuration, Reconfigure ILO IP address and reset ILO administrative password.

Now ILO configuration of ESXi host can easily be done without need of host restart using HP ESXi utilities.
HP ESXi Utilities Offline bundle for VMware ESXi 5.5 will be available as part of HP customized ESXi installer image but if it is not a HP customized ESXi image then you may need to download and install  HP ESXi Utilities Offline bundle for VMware ESXi 5. It downloads the HP ESXi Utilities Offline bundle Zip file.This ZIp file contains 3 different utilities HPONCFG , HPBOOTCFG and HPACUCLI utilities for remote online configuration of servers.

HPONCFG can be used to set up and reconfigure the iLO (Integrated Lights-Out) management controller of a server.
HPBOOTCFG can be used to set up the boot configuration for the server.
HPACUCLI can be used in the configuration of HP Smart Array controllers and attached storage

esxcli software vib install  -d /vmfs/volumes/54916ea3-2489c019-e8cd-001e0bd2583c/HP-iLO/hp-HPUtil-esxi5.5-bundle-1.5-27.zip 

Once it is installed. Browse towards the directory /opt/hp/tools and execute  the below commands to perform the below operations. Below are the available help options for HPONCFG utility

cd /opt/hp/tools/

./hponcfg -w /tmp/ilo-conf.txt

cat /tmp/ilo-conf.txt

<!– HPONCFG VERSION = “4.0-11.0″ –>
<!– Generated 11/7/2016 11:19:55 –>
<RIBCL VERSION=”2.1″>
<LOGIN USER_LOGIN=”Administrator” PASSWORD=”password”>
<DIR_INFO MODE=”write”>
<MOD_DIR_CONFIG>
<DIR_AUTHENTICATION_ENABLED VALUE = “N”/>
<DIR_LOCAL_USER_ACCT VALUE = “Y”/>
<DIR_SERVER_ADDRESS VALUE = “”/>
<DIR_SERVER_PORT VALUE = “636”/>
<DIR_OBJECT_DN VALUE = “”/>
<DIR_OBJECT_PASSWORD VALUE = “”/>
<DIR_USER_CONTEXT_1 VALUE = “”/>
<DIR_USER_CONTEXT_2 VALUE = “”/>
<DIR_USER_CONTEXT_3 VALUE = “”/>
</MOD_DIR_CONFIG>
</DIR_INFO>
<RIB_INFO MODE=”write”>
<MOD_NETWORK_SETTINGS>
<SPEED_AUTOSELECT VALUE = “Y”/>
<NIC_SPEED VALUE = “10”/>
<FULL_DUPLEX VALUE = “N”/>
<IP_ADDRESS VALUE = “0.0.0.0”/>
<SUBNET_MASK VALUE = “0.0.0.0”/>
<GATEWAY_IP_ADDRESS VALUE = “0.0.0.0”/>
<DNS_NAME VALUE = “ILOCZC8160J5H”/>
<PRIM_DNS_SERVER value = “0.0.0.0”/>
<DHCP_ENABLE VALUE = “Y”/>
<DOMAIN_NAME VALUE = “”/>
<DHCP_GATEWAY VALUE = “Y”/>
<DHCP_DNS_SERVER VALUE = “Y”/>
<DHCP_STATIC_ROUTE VALUE = “Y”/>
<DHCP_WINS_SERVER VALUE = “Y”/>
<REG_WINS_SERVER VALUE = “Y”/>
<PRIM_WINS_SERVER value = “0.0.0.0”/>
<STATIC_ROUTE_1 DEST = “0.0.0.0” GATEWAY = “0.0.0.0”/>
<STATIC_ROUTE_2 DEST = “0.0.0.0” GATEWAY = “0.0.0.0”/>
<STATIC_ROUTE_3 DEST = “0.0.0.0” GATEWAY = “0.0.0.0”/>
</MOD_NETWORK_SETTINGS>
</RIB_INFO>
<USER_INFO MODE=”write”>
</USER_INFO>
</LOGIN>
</RIBCL>

Reset the ILO from ESXi host

Browse to /opt/hp/tools and execute the below command to reset the HP ILO configuration.

./hponcfg -r 

http://www.vmwarearena.com/how-to-configure-hp-ilo-from-esxi-host/

http://h20564.www2.hpe.com/hpsc/swd/public/detail?swItemId=MTX_261d74ac60c24580aeccde8c28#tab3

http://inet6.alphasca.net/ilo-ilo2-ilo3-and-ilo4-advanced-license-activation-keys/