Authority and Additional sections (was Re: bind vs djbdns)

[Kevin Darcy]

Not to start another flame war, but I think it's a *good* thing to omit
Authority and "related" Additional section RR's in responses to recursive
queries, assuming a) RCODE=NOERROR and b) it's not a referral. The
RFC's don't *mandate* Authority or "related" Additional section contents
in these cases -- OPT, TSIG, etc. are separate mandates. Most clients
requesting recursive service don't need Authority or Additional sections,
so it's just packet bloat, and in the case of a globally-forwarding
nameserver, it just ends up putting useless referral information in its
cache that it'll likely never use.

I've already received positive feedback on a proposal to implement this in
BIND, and I plan to code and submit it once BIND 9 is released.


- Kevin

Greg Rumple wrote:

> * Ruben I Safir (ruben at sruben.dental.nyu.edu) [000831 15:03]:
> > Bernstien -
> >
> > Trying to earn a living from Free Software is not an example of Moral
> > Corruption.
> >
> > But the fact that your DNS is cutting corners is real concern.  Where
> > you hired by microsoft to undermined the internet so they can save us
> > from the chaos of a free internet not controlled by Redmond?  That's
> > what it sound like with the burly responses and absolute statement.
>
> Actually Microsoft is doing this all by themselves, without the help of
> dnscache.  Their DNS server leaves tons of things to be desired, and
> cuts plenty of corners (they don't even bother to respond with any
> additional or authority sections at all).  For example, look at this
> output.  Last I checked, dnscache is light years ahead of this, and way
> more RFC compliant.
>
> $ dig @pdc1gd1.schwab.com www.schwab.com a
>
> ; <<>> DiG 8.2 <<>> @pdc1gd1.schwab.com www.schwab.com a
> ; (1 server found)
> ;; res options: init recurs defnam dnsrch
> ;; got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 6
> ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
> ;; QUERY SECTION:
> ;;      www.schwab.com, type = A, class = IN
>
> ;; ANSWER SECTION:
> www.schwab.com.         15S IN A        162.93.203.133
>
> ;; Total query time: 111 msec
> ;; FROM: xxxxxx.xxxxxx.xxx to SERVER: pdc1gd1.schwab.com  162.93.253.70
> ;; WHEN: Thu Aug 31 20:38:40 2000
> ;; MSG SIZE  sent: 32  rcvd: 48
>
> Greg
>
> --
> Greg Rumple
> Senior Systems Developer
> UltraDNS Corporation