ITAL: 
http://wiki.openwrt.org/OpenWrtDocs/KamikazeConfiguration
config interface wan
        option ifname   eth0.1
        option proto    dhcp
        option hostname MyRouter  #This is only used if the proto is dhcp otherwise it is ignored.
v pripade openwrt na rb133 bych videl nastaveni takhle (
/etc/config/network):
config interface lan0
        option ifname   eth0
        option proto    dhcp
        option hostname MyRouter
pokud by si chtel spoustet dhcp klienta rucne, zkus 
udhcpc:
root@OpenWrt:/# udhcpc --help
BusyBox v1.8.2 (2008-01-14 22:02:18 EET) multi-call binary
Usage: udhcpc [-Cfbnqtv] [-c CID] [-V VCLS] [-H HOSTNAME] [-i INTERFACE]
        [-p pidfile] [-r IP] [-s script]
        -V,--vendorclass=CLASSID        Set vendor class identifier
        -i,--interface=INTERFACE        Interface to use (default: eth0)
        -H,-h,--hostname=HOSTNAME       Client hostname
        -c,--clientid=CLIENTID  Set client identifier
        -C,--clientid-none      Suppress default client identifier
        -p,--pidfile=file       Store process ID of daemon in file
        -r,--request=IP         IP address to request
        -s,--script=file        Run file at dhcp events (default: /usr/share/udhcpc/default.script)
        -t,--retries=N          Send up to N request packets
        -f,--foreground Run in foreground
        -b,--background Background if lease cannot be immediately negotiated
        -S,--syslog     Log to syslog too
        -n,--now        Exit with failure if lease cannot be immediately negotiated
        -q,--quit       Quit after obtaining lease
        -R,--release    Release IP on quit
        -v,--version    Display version