Subject: Re: I-D ACTION:draft-koerber-dnsind-glue-00.txt

From: "Mathias Koerber" <[email-masked]>
Date: Wed, 1 Dec 1999 07:55:14 +0800

From: Matt Crawford <[email-masked]>

|I have several questions about draft-koerber-dnsind-glue-00.txt, some
|or all of which are naive.
|
|You probably considered having a single GNUE RR type with an
|indicator of which type of address RDATA it contained.  Why did you
|prefer three types plus a query type?

I initially did think of only one GLUE record, however the change from AAAA
to
A6 indicated that there may be furute adress record types which could
potentially be used as GLUE, in which case the format of the single GLUE
record might need to be changed. A separate GLUE record type for
each A record type allows easy addition of new GLUE record types when
necessary, without having
to redefine the single record.

|
|The GLUE record types are intended to make the servers for the parent
|zone carefully distinguish glue addresses from authoritative address
|records in replies.  But the server can already tell the two apart
|when it loads a zone file, can't it?

Can it? It would have to perform checks for every A record whether a
subdomain
is being delegated that has the same label as target for an NS record. This
may be doable but labor-intensive on loading. It may get more complicated
(and result in a real performance hit) when such glue records are
changed using dynamic update.

A new record type which clearly indicated the intention of the admin sounded
better, than
trying to have the server interpret dual meanings of A records.

| And then return them in the
|careful way your draft wants?  I've just tested and some servers (eg,
|Multinet's BIND-based server) do carefully return glue only as
|additional info, while others (eg, all the root servers) do not.
|
|Do you think a similar thing needs to be done for NS records?  After
|all, the NS records for the child zone which are contained in the
|parent's zone file are not authoritative and a better set may be
|found in the child zone.

a) STUB zones can do that already
b) NS records do not have dual meaning in the parent ( ie there is no
question
that a parent NS should return an NS record in the ANSWER SECTION if it
is queried for that label/type, but with A records that usually is NOT
intended
if the record is pure GLUE)

regards

| Matt Crawford
|