Novell Open Enterprise Server 2 (OES 2) Linux
SUSE Linux Enterprise Server 10 (SLES 10)
Load dhcpd with a -d switch.
ie. /usr/sbin/dhcpd -d
The level cannot be adjusted (such as debug level 3, debug level 10, and so forth). All debug output is logged to /var/log/messages
Keywords to improve searchability: how to set dhcp dhcpd into debug level -d mode