Juergen Schoenwaelder <j.schoenwael...@jacobs-university.de> writes: > On Wed, Jul 22, 2020 at 01:46:38PM +0200, Ladislav Lhotka wrote: >> >> >> On 22. 07. 20 13:00, Juergen Schoenwaelder wrote: >> > Tom, >> > >> > my understanding is that Lada is now proposing something slightly >> > different but I am not sure what exactly, hence I asked again. >> >> Oh yes, I messed it up by mixing different things together, sorry. I >> checked again the ML archive, and the message that is relevant to this >> thread is this: >> >> https://mailarchive.ietf.org/arch/msg/netmod/PISOifrtow4oWLGW7meBBSri7nM/ >> >> The aim of that proposal was to limit the "inet:host" type to DNS names >> that are reasonable as host names, i.e. eliminate values like "." or "_". > > You are proposing to change the length restriction from 1..253 to > 2..253 following RFC 952: > > [...] Single character names > or nicknames are not allowed. > > And you add > > pattern '(.*\.)?..\-\-.*' { > modifier invert-match; > } > > to restrict things to non-reserved letter-digit-hyphen labels as per > RFC 5890. Is it clear that this second restriction applies to host > names? How do you represent internationalized host names? Perhaps we > need a collection of examples? And is the pattern correct? RFC 5890 > says: > > Reserved LDH labels, known as "tagged domain names" in some other > contexts, have the property that they contain "--" in the third and > fourth characters but which otherwise conform to LDH label rules. > > What is the '(.*\.)?' part doing in your pattern? > > Finally, would it be useful to derive a host-name type from the > domain-name type (if host-names are really a strict subset of what > domain-name allows), e.g.:
The current definition of "inet:domain-name" in 6991bis also permits the underscore character in labels, so it is not LDH. Lada > > typedef host-name { > type domain-name { > pattern '(.*\.)?..\-\-.*' { > modifier invert-match; > } > length "2..max"; > } > description > "Host names must be at least two characters long (see RFC 952) > and they are restricted to non-reserved letter-digit-hyphen > (NR-LDH) labels (see RFC ????)."; > reference > "RFC 952: DoD Internet Host Table Specification > RFC ????: ????"; > } > > /js > > -- > Juergen Schoenwaelder Jacobs University Bremen gGmbH > Phone: +49 421 200 3587 Campus Ring 1 | 28759 Bremen | Germany > Fax: +49 421 200 3103 <https://www.jacobs-university.de/> -- Ladislav Lhotka Head, CZ.NIC Labs PGP Key ID: 0xB8F92B08A9F76C67 _______________________________________________ netmod mailing list netmod@ietf.org https://www.ietf.org/mailman/listinfo/netmod