Generating IPv6 EUI64 based addresses

[Robert Elz <kre%munnari.OZ.AU@localhost>]

What do I have to tell dhcpcd in order to have it
generate me plain old ordinary EUI-64 type addresses
for IPv6 (the way they were originally specified) ?

Currently (on one test Xen DomU - hence their weird MAC addr)
I am getting...

        address: 76:d0:2b:91:ab:03
        inet6 fe80::37a1:2259:66d1:de9b%xennet0 prefixlen 64 scopeid 0x1
        inet6 2001:3c8:9009:181:251a:3362:ec98:db5 prefixlen 64
        inet6 2001:3c8:9009:181:1407:dac:dc89:3a56 prefixlen 128

I'd much prefer to have

	inet6 fe80::74d0:2bff:fe91:ab03
	inet6 2001:3c8:9009:181:74d0:2bff:fe91:ab03

(and I have no idea what the /128 is about, it doesn't seem useful,
so could just go away.)   (Aside: those were hand computed EUI-64
based addrs, if I made an error in that, I do not mean I need that
error duplicated - whatever the correct EUI-64 would be is the aim.)

Having the same low bits for the LL and global addresses improves NDP
(only one multicast addr needed).

If there is some good reason that EUI-64 addrs are impossible (if it
is just a matter of altering the MAC addr, I'll do that) then at least
could the address be stable - currently if I reinstall (keeping the same
MAC addr, but everything else new - it is a test system) I get a
different set of addresses every time.  Fortunately just a reboot does
not seem to cause that.

kre