BusyBox v1.17.1 (2010-08-25 06:09:53 NOVST) multi-call binary.

Usage: udhcpc [-fbnqvoCR] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE]
[-H HOSTNAME] [-c CID] [-V VENDOR] [-O DHCP_OPT]...

-i,--interface IFACE	Interface to use (default eth0)
-p,--pidfile FILE	Create pidfile
-r,--request IP		IP address to request
-s,--script PROG	Run PROG at DHCP events (default /usr/share/udhcpc/default.script)
-t,--retries N		Send up to N discover packets
-T,--timeout N		Pause between packets (default 3 seconds)
-A,--tryagain N		Wait N seconds after failure (default 20)
-f,--foreground		Run in foreground
-b,--background		Background if lease is not obtained
-S,--syslog		Log to syslog too
-n,--now		Exit if lease is not obtained
-q,--quit		Exit after obtaining lease
-R,--release		Release IP on exit
-a,--arping		Use arping to validate offered address
-O,--request-option OPT	Request DHCP option OPT (cumulative)
-o,--no-default-options	Don't request any options (unless -O is given)
-x OPT:VAL		Include option OPT in sent packets (cumulative)
-F,--fqdn NAME		Ask server to update DNS mapping for NAME
-H,-h,--hostname NAME	Send NAME as client hostname (default none)
-V,--vendorclass VENDOR	Vendor identifier (default 'udhcp VERSION')
-c,--clientid CLIENTID	Client identifier (default own MAC)
-C,--clientid-none	Don't send client identifier