OR: Reverse DNS

Hi,

I know there are lots of people who know out there...

About 4 weeks ago I changed my name servers from 800hosting to easydns, why
then does a reverse DNS of my IP 69.41.161.159 still show 800hosting?

http://www.dnsstuff.com/tools/traversal.ch?domain=159.161.41.69.in-addr.arpa&type=PTR

[I know the IP number appears in reverse in the URL, but I know not why]

I know that it takes time to propogate, but it's weeks now. Any ideas?

 

Kevin Stone wrote:

Oops in subject, for OR: read OT:

 

Because your ISP maintains the reverse DNS zone and nobody has told them to
update the record.
--
Alex

Hermes: "We can't afford that! Especially not Zoidberg!"
Zoidberg: "They took away my credit cards!"

www.drzoidberg.co.uk www.ebayfaq.co.uk

 

Can you explain this a little more?

Domain is with netsol as registrar, so I'm in control of name servers. All 5
point to easydns, no reference to 800hosting. So, why is the reversedns not
looking at easydns.

Or to put it another way, how do I solve the problem?

Cheers.

 

The domain yourdomain.com is registered with netsol and delegated to
easydns's nameservers.

The domain 161.41.69.in-addr.arpa has a completely unrelated delegation,
so changing your forward DNS won't have any effect on the reverse.

What *is* the problem?

 

OK, fair enough, how do I change the reverse then? Over the many years (6+)
that the domain has been around, it's been with many hosts. It's showing the
last one (800hosting).

The problem (if it could be called one), is that the IP reverse DNS's to
wap.brainbashers.com and not mail.brainbashers.com

 

I see...

mail.brainbashers.com. 43200 IN A 69.41.161.159

161.41.69.in-addr.arpa. 80 IN NS ns4.1-800-hosting.com.
161.41.69.in-addr.arpa. 80 IN NS ns1.1-800-hosting.com.
161.41.69.in-addr.arpa. 80 IN NS ns2.1-800-hosting.com.
161.41.69.in-addr.arpa. 80 IN NS ns3.1-800-hosting.com.

159.161.41.69.in-addr.arpa. 600 IN PTR wap.brainbashers.com.

So it looks as though, regardless of who provides your _forward_ DNS,
the reverse DNS for that IP is provided by 1-800 hosting. Suggesting
that that's where your server really is. So you'll need to get in
touch with 1-800 hosting and ask them to change the PTR record for
that IP to something else.

If that site is now hosted by somebody else, then I'd expect (unless
you have your own IP address space) the IP to change as well, in which
case the holder of the reverse DNS zone will also change. But I get
the feeling you've not actually moved it anywhere, just changed the
delegation for brainbashers.com.

 

OK, as far as I can tell then, the batch of IPs which I have (which are
owned by 800hosting) are reversed DNSed back to 800hosting and in turn then
have a file which stores the domain on their network which sits on this IP.
If this is the case, then it can stay as it is.

Cheers.

 

Yes, the reverse zone is delegated to 800hosting. Their nameservers
store PTR records for the IPs within that zone, mapping IPs to hostnames.
You can either ask 800hosting to change the PTR record, or leave it.

 

Which is because it is in a subnet owned by 1-800 hosting - and the way
that DNS works it's very difficult (ie functionally impossible) to
split out divisions smaller than a class-C to anyone else.

And they will laugh at you - DNS reverse zone ownership can't be done
on single IP addresses - just zones.

That they can do is put the hostname of your other provider in their
reverse DNS so that the resolution works properly - but they can't
change the ownership of the reverse because it is in the middle of
their range.

Phil.

 

I don't think they'll laught at you. It's been possible for years,
though rarely you'll find someone who knows / cares enough to do it.

See here for details:
http://www.simpledns.com/help/index.html?df_reverse.htm

Effectively, they create a new zone, which they delegate to your name
servers. They then CNAME your PTR records to that zone. I have done
it, and it does work, but not very common. If you have have so few IP
addresses it's a bit unlikely they'll bother.

/Craig

 

Yeah, I've used this method (per RFC2317) for years, currently with
Claranet and previously with PSINet. It works a treat but, like you say,
I doubt the "budget" domain hosts will be interested in setting this up
as it's a relatively uncommon requirement, and there's the vague
potential for customer-naughtiness afforded by giving random scrotes
full control of their reverse DNS.

 

Yes, I know this. I've set up and/or operated several RIPE LIRS.

Er, I mean change the actual PTR record, not try and kludge it into
being pseudo-delegated elsewhere.