Good morning! What is the status here? Thanks, Martin On Mon, Feb 5, 2024 at 8:53 PM Chuck Lever III <chuck.lever@xxxxxxxxxx> wrote: > > > > > On Feb 5, 2024, at 11:17 AM, Trond Myklebust <trondmy@xxxxxxxxxxxxxxx> wrote: > > > > On Mon, 2024-02-05 at 15:13 +0000, Chuck Lever III wrote: > >> > >> > >> A DNS label is just a hostname (fully-qualified or not). It > >> never includes a port number. > >> > >> According to RFC 8881, fs_location4's server field can contain: > >> > >> - A DNS label (no port number; 2049 is assumed) > >> > >> - An IP presentation address (no port number; 2049 is assumed) > >> > >> - a universal address > >> > >> A universal address is an IP address plus a port number. Therefore > >> a universal address is the only way an alternate port can be > >> communicated in an NFSv4 referral. > > > > That's not strictly true. RFC8881 has little to say about how you are > > to go about using the DNS hostname provided by fs_locations4. There is > > just some non-normative and vague language about using DNS to look up > > the addresses. > > > > The use of DNS service records do allow you to look up the full IP > > address and port number (i.e. the equivalent of a universal address) > > given a fully qualified hostname and a service. While we do not use the > > hostname that way in the Linux NFS client today, I see nothing in the > > spec that would appear to disallow it at some future time. > > We absolutely could do that. But first a service name would need to be > reserved, yes? > > https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=dns > > > -- > Chuck Lever > >
