[root@monitorti plugins]# ./check_dhcp -h
check_dhcp (nagios-plugins 1.4.5) 1.6
Copyright (c) 2001-2004 Ethan Galstad (nagios@nagios.org)
Copyright (c) 2001-2006 Nagios Plugin Development Team
        <nagiosplug-devel@lists.sourceforge.net>

This plugin tests the availability of DHCP servers on a network.


Usage:check_dhcp [-s serverip] [-r requestedip] [-t timeout] [-i interface] [-v]

Options:
 -h, --help
    Print detailed help screen
 -V, --version
    Print version information
 -v, --verbose
    Show details for command-line debugging (Nagios may truncate output)
 -s, --serverip=IPADDRESS
    IP address of DHCP server that we must hear from
 -r, --requestedip=IPADDRESS
    IP address that should be offered by at least one DHCP server
 -t, --timeout=INTEGER
    Seconds to wait for DHCPOFFER before timeout occurs
 -i, --interface=STRING
    Interface to to use for listening (i.e. eth0)
[root@monitorti plugins]#