On Sun, Nov 15, 2009 at 12:06:44AM +0100, ?????????? ???????????????? wrote: > > However, there may be > > situations where hexadecimal representation is chosen to meet certain > > needs. Addressing those needs is out of the scope of this document. > > It's rather vague, and I think the recently added Section 3.2.5 offers an > example that's close having such needs. If for some reason a textual > comparison of addresses is done in the course of a protocol (don't know > how likely it is, but can certainly happen), a strictly canonical format > is required, and Section 5 currently gives some leeway in this matter > (since different systems may have different knowledge about existing > address types). Perhaps, especially since this is a standards track > document now, such a strict format should be specified, to save protocol > developers the trouble of doing it themselves. > > I think that for such a "really canonical" representation, we can just > forbid using the mixed notation. The reasons for this are that it's the > simplest definition, the easiest to implement and doesn't single out any > particular transition technologies. An alternative would be to mandate > mixed notation for IPv4-mapped and IPv4-compatible addresses and > hexadecimal representation for everything else, for compatibility with > current implementations of inet_ntop. However, I don't think that such > compatibility matters much, because there are no consistency requirements > for inet_ntop and to ensure canonicity developers will be required to > implement their own functions, anyway.
For what its worth, draft-ietf-netmod-yang-types-04.txt only uses the hexadecimal format for the ipv6-address data type. This simplifies things since all IPv6 addresses have the same format - and it does not matter how an address was generated when it comes to questions such as ordering of addresses. I would prefer if the wording in this document allows for the single representation approach taken in the above mentioned document. /js -- Juergen Schoenwaelder Jacobs University Bremen gGmbH Phone: +49 421 200 3587 Campus Ring 1, 28759 Bremen, Germany Fax: +49 421 200 3103 <http://www.jacobs-university.de/> -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
