Date:        Mon, 8 Apr 2002 13:48:40 +0200 (MEST)
    From:        Hubert Feyrer <hubert.feyrer@informatik.fh-regensburg.de>
    Message-ID:  <Pine.GSO.4.21.0204081347510.1720-100000@rfhpc8317>

  | On Sun, 7 Apr 2002, Sean Davis wrote:
  | > ifconfig tl0 inet6 2001:c0a8:4501:0001:0008:c7ff:fea4:a940 prefixlen 64 up
  | > 
  | > The MAC address of the card is 00:08:c7:a4:a9:40, and the IPv4 address is
  | > 192.168.69.1 - Is it OK to make the IPv6 address from the IPv4 if you're not
  | > doing 6to4, or should I be doing something differently?
  | 
  | No need to use the v4 address. The above looks fine

Sean did use the IPv4 address (the c0a8:4501 part).   And no, you can only
do that if you're using 6to4 (in which case the first 16 bits would be 2002).

You need to get the prefix (/48) to use from your IPv6 network provider
(wherever you're going to be sending IPv6 packets).  If you don't have one
of those (you have no global IPv6 connectivity) then you should be using
link local addresses exclusively if you have just one link (no need to
assign those, the system will pick its own, always), or site local addresses
if you have several nets connected by (IPv6) routers (like NetBSD boxes).

kre