[arin-ppml] GUA vs ULA vs ?

David Farmer farmer at umn.edu
Tue Mar 30 16:54:44 EDT 2010

Steve Bertrand wrote:
> On 2010.03.29 22:18, David Farmer wrote:
>> Steve Bertrand wrote:
>>> Perhaps IANA should be approached for a 1918 v6. Perhaps I'm out of my
>>> league ;)
>> Essentially, ULA RFC 4193 is the IPv6 replacement for RFC 1918, it
>> provides for random local assignment within the prefix FD00::/8, it
>> provides significant statistical uniqueness, but not a guarantee of
>> uniqueness.
> Ahhh. I see.
>> ULA-C (Central) is an expansion of this intended to
>> guaranteed uniqueness through a centrally registry with assignments made
>> within the prefix FC00::/8, and reverse DNS delegation should be
>> available if wanted.

I should have added that ULA-C is not currently defined in any RFC, the 
whole prefix FC00::/7 is defined for ULA in RFC 4193, but FC00:/8 is 
technically reserved, only FD00::/8 has been defined so far. There have 
been a number drafts looking to define centrally assigned ULA (ULA-C), 
the most current one is at the following URL;


David Farmer               Email:farmer at umn.edu
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