classless delegation [Re: IP address fee??]
Brad Knowles
brad.knowles at skynet.be
Fri Sep 6 21:04:36 UTC 2002
At 10:28 PM +0200 2002/09/06, Jeroen Massar wrote:
> Yes, they get returned, whoo hoo:
> 8<---------
> jeroen at purgatory:~$ dig 192.122.109.193.in-addr.arpa any
That could just be your local caching nameserver. You need to
ask his nameservers the same question:
% dig @ns.dataloss.nl. 192.122.109.193.in-addr.arpa any
; <<>> DiG 9.2.1 <<>> @ns.dataloss.nl. 192.122.109.193.in-addr.arpa any
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 56202
;; flags: qr aa rd; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 2
;; QUESTION SECTION:
;192.122.109.193.in-addr.arpa. IN ANY
;; ANSWER SECTION:
192.122.109.193.in-addr.arpa. 2560 IN SOA ns.dataloss.nl.
hostmaster.192.122.109.193.in-addr.arpa. 1031343156 16384 2048
1048576 2560
192.122.109.193.in-addr.arpa. 259200 IN NS ns.dataloss.nl.
192.122.109.193.in-addr.arpa. 259200 IN NS ns3.dataloss.nl.
;; ADDITIONAL SECTION:
ns.dataloss.nl. 259200 IN A 193.109.122.194
ns3.dataloss.nl. 86400 IN A 193.109.122.215
;; Query time: 73 msec
;; SERVER: 193.109.122.194#53(ns.dataloss.nl.)
;; WHEN: Fri Sep 6 23:00:13 2002
;; MSG SIZE rcvd: 171
Fortunately, in this case, we still get the same information.
> Or any other IP you would randomly pick actually... show me one that
> doesn't have this behaviour :)
That's really more a factor of the nameserver which provides the
answer -- did you ask their servers directly, or did you ask a local
caching nameserver which could have answered some or all of that from
cache?
> 60.1.0.10.in-addr.arpa. CNAME bla-reverse.example.org.
> bla-reverse.example.org. PTR bla.example.org.
> bla.example.org. A 10.0.1.60
>
> What's wrong with that? No RFC against it ;)
Are you sure about that? IIRC, the definitions of CNAME records
and what they can point to are pretty strict.
> You are actually saying that one can't setup a DNS for a reverse host
> then ;)
No, just saying that if you're going to do it, you should do it
the proper way -- using RFC 2317.
> Cool, why does it work then? <grin>
Just because something hasn't actually been made officially
illegal doesn't mean that it's not a really bad idea.
--
Brad Knowles, <brad.knowles at skynet.be>
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
-Benjamin Franklin, Historical Review of Pennsylvania.
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O- M++ V PS++(+++) PE- Y+(++) PGP>+++ t+(+++) 5++(+++) X++(+++) R+(+++)
tv+(+++) b+(++++) DI+(++++) D+(++) G+(++++) e++>++++ h--- r---(+++)* z(+++)
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