Re: ULA scope [draft-ietf-6man-rfc3484-revise-05.txt]

[Mark Andrews <[e-mail]>]

In message <01f401cd05dc$20914df0$61b3e9d0$@[e-mail]>, "Marc Lampo" write
s:
> Allow me to clarify with an example.
> 
> In my IP(v4) experience, I have a customer with offices over multiple
> Continents - private address space in use everywhere -
> site-to-site VPN's (== connecting networks) connect the offices.
> 
> If I map to IPv6 this might be one /48 ULA range;
> Some networks in central HQ, others remotely, behind site-to-site VPN.
> 
> --> if one end-node in one network wants to reach another,
>      in another network, its traffic must travel through the VPN.
> 
> Please observe that using public addresses (not using ULA)
> might do away with address selection "challenges"
> but would imply that networks on all continents will have to be
> renumbered if the central HQ changes ISP (and hence : public IPv6
> addresses).
> Something I'd like to avoid ...
> 
> Kind regards,
> 
> Marc Lampo

Well with a single ULA you have 65536 /64 sized networks to use
where ever you want.  You have ULA:0000/56 in Paris, ULA:0100/55
in New York.  You don't have to keep things bit aligned but it
helps.  65536 prefixes isn't a lot of routing information.  Think
of it in IPv4 terms as 10/8 and you are handing out /24 for each
subnet except you know you won't need more than /24 ever.

Mark
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
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