Just what *is* a hostname (rfc952/1123, etc)

[Jim Reid]

>>>>> "David" == David Carmean <dlc-bu at halibut.com> writes:

    >> Perhaps a better way to answer this is that non-fully-qualified
    >> name are just an abbreviation mechanism that can be used in
    >> certain contexts (e.g. in zone files they're just a shorthand
    >> for the name with the $ORIGIN appended, and when invoking a
    >> resolver it will try appending the suffixes in the search
    >> list).  As far as on-the-wire protocols are concerned, names
    >> are always fully qualified.

    David> Which appears to have the interesting side-effect of making
    David> it impossible to add relative names to a zone via DDNS,
    David> either as owner names or in the RDATA.  But RAM and disk
    David> are cheap these days, and it might cut down on mistakes (?).

The wire protocol has to use fully qualified domain names so that they
can be uniquely identified. The server doesn't have to establish and
maintain any state information about what each client thinks is its
current domain origin.