Modifications to the inet6num in the RIPE Database

  Guy, Engin,
  
  thanks a lot for the explanation!

  Guy said:
  
>Finally, you can only have one of these constructs per address.  This is
>common sense really since, if you have 3ffe::aaaa::bbbb, you cannot tell
>how many zeroes are replaced with the first pair of colons and how many
>by the second.  There is no convention (AFAIK) for which block would be
>written out in full.  Personally, since I am lazy, I choose to write out
>the fewer number of zeroes (remembering that I only need one zero per
>block of 4 hex digits).
>
>So, some examples of IPv6 addresses are...
>
>3ffe:1100:0:c00::/52
>= Note the :0: because there is a :: later in the address

  Engin added:

>The algorithm we use translates "5:0:0:78:0:0:0:0"
>into "5:0:0:78::" but not "5::78:0:0:0:0". Of course,
>both are legal, but we choose to double-colonize the 
>last group of zeros, and all prefixes are normalized
>according to this and then put into the registry.

  which already gives us two compatible but different ways to deal with
  that, and 

>But I don't know what 6bone registry does.

  interesting, indeed.
  
  Taking this one step further, and looking back at what we did with IPv4,
  where it would be feasible to say 131.130/16, implying 131.130.0.0/16,
  I wonder if it wouldn't again be worthwhile to restrict the use of these
  shorthand notations in the Address Registry?
  
  Is there a danger for braking something by _not_ allowing the "::"
  construct in the registry at all, or - in particular - not _in the
  middle_ of a prefix?
  
  Wilfried.
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  Wilfried Woeber                :  e-mail: Woeber at CC.UniVie.ac.at
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