login as root
check what interfaces you would like use (ifconfig -a)..

to enable the interface for dhcp do this as root

cat /dev/null > /etc/hostname.XXX
cat /dev/null > /etc/dhcp.XXX

where XXX is the name of the network interface like hme0, qfe0, eri0, ce0, bge0 or something like that..

after you are done with that simple reboot or issue the following command to make the change right away if you cant reboot

ifconfig XXX dhcp start

The following commands can be used to display the DHCP lease information and release the DHCP lease, respectively:

ifconfig XXX dhcp status
ifconfig XXX dhcp release

/Peter