Re: [DNSOP] DNS Terminology: Glue

[Tony Finch <[e-mail]>]

Shumon Huque <[e-mail]> wrote:
>
> It might be worth also clarifying another thing. The definition states
> "These RRs are only necessary if", but doesn't clearly include or
> exclude the possibility that other address records for NS names that
> don't sit below the zone cut, and were gratuitously provided in the
> referral response, qualify to be called 'glue'. I think they should not
> be called glue (they don't meet my intuitive understanding of the
> meaning of 'glue', as gluing up a hole in the resolution path). But
> clarity on this point would be welcome.

In the additional section of a referral, address records for name servers
that are not in the delegated zone are not glue records. This is implied
by RFC 1034 section 4.3.2:

            Copy the NS RRs for the subzone into the authority
            section of the reply.  Put whatever addresses are
            available into the additional section, using glue RRs
            if the addresses are not available from authoritative
            data or the cache.  Go to step 4.

Section 4.2.1 classifies zone data into authoritative data, apex
authoritative data, delegations, and glue, and says glue is
non-authoritative. It also says glue records are only used as part of a
referral response, which is not the case for authoritative name server
address records.

Tony.
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