> On Mon, Jun 30, 2008 at 05:49:18AM -0700, > David Conrad <drc@xxxxxxxxxxxxxxx> wrote > a message of 11 lines which said: > > > Speaking technically, how would you distinguish the top-level domain > > "127.0.0.1" from the IP address 127.0.0.1? > > A word while passing here: is there a document (RFC, Posix standard, > whatever) which says which is the right result in such a case? > > There are protocol-specific rules. RFC 3986, section 3.2.2, clearly > says that the IP address wins and so your example would be regarded > as the localhost IP address, wether the TLD ".1" is delegated or no. > > But I do not find generic rules. > > RFC 3493 which specifies getaddrinfo is not very clear. Section 6.1 > apparently does not address your issue. > > So, I would say there is a normalization failure here: since 127.0.0.1 > can be a domain name and an IP address, we really should have > precedence rules for such case (instead of asking ICANN to solve them > by forbidding all-numeric TLD). I think you will find that getaddrinfo() implementations catch IP address rather than look them up. The question is more what they catch rather than when they catch. For IPv6 it is pretty straight forward. There is a recommend a followed syntax. IPv4 on the other hand has lots of history involved. OS's with lots of history tend to support very liberal syntaxes. OS's with not so much history tend to be limited to dotted decimal quad. ICANN is in a position to look at what the various OS's accept and rejects TLD's application that will potentially conflict with the existing practice of any current OS. This will prevent users that switch OS's and use something other than dotted decimal quad getting a match in the DNS when the new OS is not as permissive as the old OS. > _______________________________________________ > Ietf mailing list > Ietf@xxxxxxxx > https://www.ietf.org/mailman/listinfo/ietf -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: Mark_Andrews@xxxxxxx _______________________________________________ Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf