Subject: RR distribution by type?

From: "Larson, Matt" <[email-masked]>
Date: Mon, 2 Apr 2001 16:27:01 -0400

Hi, folks.

Has anybody ever done or seen a (recent) survey of how various RR types are
distributed "in the wild" in real-world zones?  Ideally, I'd be interested
in a histogram of RR types for the entire name space.  Obviously A and PTR
would be the two most popular, probably followed by CNAME, MX, NS and SOA
(in that order?).  And then all the lesser-used RRs--but what I'm really
wondering is how used some of the less-used really are.

Any data or thoughts would be welcome.

Matt
--
Matt Larson <[email-masked]>
VeriSign Global Registry Services / www.verisign-grs.com

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From: "Brian W. Spolarich" <[email-masked]>
Date: Mon, 2 Apr 2001 17:05:35 -0400

| Has anybody ever done or seen a (recent) survey of how various RR
| types are
| distributed "in the wild" in real-world zones?  Ideally, I'd be interested
| in a histogram of RR types for the entire name space.  Obviously A and PTR
| would be the two most popular, probably followed by CNAME, MX, NS and SOA
| (in that order?).  And then all the lesser-used RRs--but what I'm really
| wondering is how used some of the less-used really are.

  I once thought I saw a PX record in the wild, but it may have been
an MX of a different color.  :-)

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From: Edward Lewis <[email-masked]>
Date: Mon, 2 Apr 2001 17:32:43 -0400

The distribution might vary widely by depth, etc., of the zone.

You could probably start a survey by using the publicly available high-up
zones (root, arpa, etc.).

Not to be facetious, I'd be curious what the distribution is in .com
(percentages would be good enough).  This would impact a lot of areas -
some places are sensitive to how many zones a server serves (ie the ratio
of NS to glue A's).

>Any data or thoughts would be welcome.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Edward Lewis                                                NAI Labs
Phone: +1 443-259-2352                      Email: [email-masked]

Dilbert is an optimist.

Opinions expressed are property of my evil twin, not my employer.

---

From: Peter Koch <[email-masked]>
Date: Thu, 05 Apr 2001 19:28:15 +0200

> distributed "in the wild" in real-world zones?  Ideally, I'd be interested

Here's an excerpt of what was discovered during the latest RIPE DNS hostcount
<http://www.ripe.net/ripencc/pub-services/stats/hostcount/> for the TLD DE
<http://www.TechFak.Uni-Bielefeld.DE/~pk/dns/hostcount/latest.html>.

	38506954 total
	13173185 A
	11301138 NS
	 7970557 MX
	 4916802 SOA
	  829975 CNAME
	  202454 HINFO
	   90459 TXT
	    9544 PTR
	    4101 SRV
	    2465 WKS
	    2456 RP
	    1105 AAAA
	    1037 MB
	     943 MR
	     621 LOC
	      50 A6
	      23 KEY
	      18 MINFO
	      17 AFSDB
	       2 NSAP
	       2 MG

The figures for A, NS and SOA are off by a factor of two (see ref'd document
for an explanation). Some observations:

o HINFO is rather popular

o PTR RRs are due to RFC1101 and classless delegation (RFC2317) pointing
  into the "forward" zone

o SRV is still rather low, but the survey only covers some 80 % (== 2.45
  million) of the zones and only sees the externally visible part of the
  namespace

o Given the distribution of AAAA and A6 - does this call for combined
  operations?

Finally, the question whether a certain RR type is "used" remains unanswered
for most of them, because you'd have to take into account both zone population
and query patterns.

-Peter