udhcpc6

A DHCPv6 client talks to ff02::1:2 from its link-local address, on UDP 546 to 547. Stateful: Solicit, Advertise, Request, Reply, and the device holds a leased /128. Stateless (-l): one Information-request and its Reply, settings only, the address staying with SLAAC. Which one a device uses is the router advertisement's M and O flags. DHCPv6 never gives a default route: that comes from the advertisement.

udhcpc6 command usage

udhcpc6 -i CARD [-l] [-n] [-q] [-s SCRIPT]

Options

-i eth0

the card to ask on

-l

stateless: an Information-request for settings, no address

-n -q

give up if nobody answers; exit once answered

-s /etc/udhcpc6.script

the script that is handed the answer (prints it and installs the address)

udhcpc6 examples

udhcpc6 -i eth0 -l -q -n -s /etc/udhcpc6.script

Asks for DNS servers and the search domain only.

udhcpc6 -i eth0 -q -n -s /etc/udhcpc6.script

Leases an address from the server's pool and installs it as a /128.

Pitfalls

• A device asks DHCPv6 only when the advertisement's M or O flag says so; with both off the server is never asked.

Run it on real machines