On Wed, 2010-08-04 at 10:43 -0400, James Knott wrote:
Adam Tauno Williams wrote:
This page allows you to generate and then 'register' your IPv6 ULA (Unique Local Address) RFC4193 prefix. Note that this does not concern ULA-Central, though this system could easily handle that too. When you have registered your ULA prefix here, it allows others to check up if they accidentally generated the same prefix, before using it. This should absolutely minimize the number of collisions for ULA space. We hope that everybody using ULA prefixes register their prefixes here, to avoid these collisions. I thought one of the points of unique local addresses was they weren't supposed to be routed off the local network. If you're experiencing
collisions, you're misusing them.
True. But you are mis-defining "local" in this case. Local means a
"site" or "campus" or "organization" which could have multiple networks
- and just like IPv4's 10/8 and 192.168/16 ULAs can be sub-netted. This
just avoids this issue [which I've encountered several times] where one
organization absorbs another [creating a new, larger, "local" network]
to discover that both organizations used overlapping private IPv4
networks [typically 192.168.1.x]. So things must then be NAT'd
internally [ick!] or renumbered [painful]. This matters especially for
truly "private" networks that may never have a 'public' network
assignment.
--
Adam Tauno Williams