Become superuser on the server system.
Stop the DHCP server temporarily.
# svcadm disable -t svc:/network/dhcp-server
You can also use DHCP Manager or dhcpconfig to stop the server.
Restart the daemon in debugging mode.
# /usr/lib/inet/in.dhcpd -d -v
You should also use any in.dhcpd command-line options that you normally use when you run the daemon. For example, if you run the daemon as a BOOTP relay agent, include the -r option with the in.dhcpd -d -v command.
When run in debugging mode, the daemon displays messages to your screen while processing DHCP or BOOTP requests. See Output from the DHCP Server in Debugging Mode for information about server debugging mode output.