frnkblk at iname.com
Thu Jun 4 10:03:52 UTC 2009
Just to add to the excellent comments already posted here, using +trace can
be helpful in seeing how things are delegated. I use the paid version of
DNSreports to provide a non-tech friendly version of the delegation, which
has the added benefit of beings able to trace it down other "branches" as
well, when multiple NS servers are listed.
From: bind-users-bounces at lists.isc.org
[mailto:bind-users-bounces at lists.isc.org] On Behalf Of Michael Milligan
Sent: Wednesday, June 03, 2009 8:42 PM
To: Scott Haneda
Cc: Bind Mailing
Subject: Re: PTR delegation
Scott Haneda wrote:
> On Jun 3, 2009, at 11:53 AM, Scott Haneda wrote:
>> 1) Is it possible to determine what ip range/space has been given to
>> user of that IP space? For example, in a colocation environment, I am
>> given say, a /24, and I want to look that up and see if it really is a
>> /24. I have found the -x option which is making life a lot easier to
>> find PTR records.
Only your local router knows for sure. DNS reverse-mapping delegation
and routes in the routing tables often have little or no relation to
each other. They are used for entirely different purposes, of course.
>> 2) Given an IP that does not have a PTR, how do I determine if it has
>> been "sub delegated" (?) to the user of that IP? I need to learn
>> whether or not I need to contact the IP provider, and ask for a PTR
>> record, or if I need to add one in myself.
Follow the delegations. Or find where a missing delegation should be...
> I was thinking and testing, and I believe I can answer part of my own
> question, but please correct and advise where I am wrong.
> Given an ip of 126.96.36.199
> $dig -x 188.8.131.52
> 184.108.40.206.in-addr.arpa. 3589 IN PTR capone.hostwizard.com.
> So I clearly have a PTR, but I want to see who has been delegated
> control of the PTR.
> Dropping the trailing 2
> $dig 37.84.64.in-addr.arpa NS
> 37.84.64.in-addr.arpa. 3538 IN NS ns1.nacio.com.
> 37.84.64.in-addr.arpa. 3538 IN NS ns3.nacio.com.
> 37.84.64.in-addr.arpa. 3538 IN NS ns2.nacio.com.
> This to me looks like nacio.com in this case is going to control the PTR
Zone (not plural), yes.
> I can go to arin.net and do a lookup there, and find that I have been
> dished out a /26, how do I use dig to get that same answer?
You really can't. See above. All you can do is follow the delegation
path and see where it ends. In the case of a *routed* subnet smaller
than a /24 prefix, then you may or may not be able to get it delegated
to you in DNS ala RFC 2317 depending on the competence or desire/will of
your co-lo provider to do it.
Michael Milligan -> milli at acmeps.com
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