udhcp

後面要記得接-i這個參數

ex: udhcp -i ath0


root@OpenWrt:/etc/wing# udhcpc -h
udhcpc: option requires an argument -- h
BusyBox v1.18.4 (2011-04-23 14:11:18 CST) multi-call binary.

Usage: udhcpc [-fbnqoCR] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE]
[-H HOSTNAME] [-V VENDOR] [-x OPT:VAL]... [-O OPT]...

-i,--interface IFACE Interface to use (default eth0)
-p,--pidfile FILE Create pidfile
-s,--script PROG Run PROG at DHCP events (default /usr/share/udhcpc/default.scr)
-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
-n,--now Exit if lease is not obtained
-q,--quit Exit after obtaining lease
-R,--release Release IP on exit
-S,--syslog Log to syslog too
-O,--request-option OPT Request option OPT from server (cumulative)
-o,--no-default-options Don't request any options (unless -O is given)
-r,--request IP Request this IP address
-x OPT:VAL Include option OPT in sent packets (cumulative)
Examples of string, numeric, and hex byte opts:
-x hostname:bbox - option 12
-x lease:3600 - option 51 (lease time)
-x 0x3d:0100BEEFC0FFEE - option 61 (client id)
-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-none Don't send MAC as client identifier