der Mouse wrote: > Why? How is it a favor to anyone to allow some illegal names but not > others? (Of course, I don't entirely understand why check-names is > optional at all; I can't see how it's a favor to anyone to ever accept > illegal names....) First, according to RFC 1035's recommended grammar, the following DNS names are invalid: 3.206.238.207.in-addr.arpa www.inria.fr io.com . . . the first because it contains labels beginning with digits, and the others because they contain two-letter labels. Second, although it is by no means clear, it appears that RFC 1035 merely *recommends* the use of domain names that conform to the grammar, saying, "The following syntax will result in fewer problems with many applications that use domain names"; it does not require it. This grammar is followed by a statement saying, "The labels must follow the rules for ARPANET host names," followed by some explication of what that means. It is unclear whether this means that labels must follow these rules in order to conform to the recommended grammar or that labels must follow these rules to conform to the requirements of the RFC. All of this is in a section labeled, "2.3.1. Preferred name syntax". Further down, in section 5.1 where the format of the database files is defined, it is stated, "Quoting conventions allow arbitrary characters to be stored in domain names." The quoting conventions described have no purpose other than to allow the violation of the recommendations of section 2.3.1. Are there other RFCs that describe allowed syntax for domain names? The following RFCs are listed as updating RFC1035: 1101 1183 1348 1876 1982 1995 1996 2065 2181 2136 2137 2308 I have only read a few of these. -- <kragenat_private> Kragen Sitaker <http://www.pobox.com/~kragen/> TurboLinux is outselling NT in Japan's retail software market 10 to 1, so I hear. -- http://www.performancecomputing.com/opinions/unixriot/981218.shtml
This archive was generated by hypermail 2b30 : Fri Apr 13 2001 - 14:48:13 PDT