PTR records are not being applied (thus not resolving)

[muddrake]

In the DNS control pane for my primary domain, I have the following listed;

##.###.##.## / 24 PTR mydomain.com.

Yet, when a reverse DNS lookup is done against my ip address, only the ISPs PTR records are returned.

Further, if I run an NSLOOKUP with a querry for the PTR records, or check dnsstuff.com for it, no records are found.

In /var/named/run-root/var is a file called
##.###.##.in-addr.arpa, and it contains a list of records like so...


$TTL 300

@ IN SOA mydomain.com. mydomain.com. (
1132326628 ; Serial
10800 ; Refresh
3600 ; Retry
604800 ; Expire
300 ) ; Minimum

IN NS mydomain.com.
212 IN PTR domain1.org.
211 IN PTR mydomain.com.
212 IN PTR domain2.org.
212 IN PTR domain3.com.
....


etc.

any ideas why i'm not able to get the PTR records to actually be applied?

--
Gary

 

[phoenixisp]

In most cases the ISP handles all rDNS, which basically overrides your settings. Contact your ISP about this, especially if you have less than a C block of IPs.

 

[muddrake]

I thought the ISP was supposed to forward RDNS requests to the registered nameserver?

Besides, I've contacted them, and they are saying that it's something on my end. (not that that means anything necessarily)

--
Gary

 

[Who-m3]

When utilizing DNSStuff to look up the records, does it indicate it's checking your specific nameservers?

i.e.

Asking NS4.FDCSERVERS.NET. for x.xxx.xx.208.in-addr.arpa PTR record:
ns4.fdcservers.net [66.90.66.138] says to go to ns1.virt-host.com. (zone: x.xxx.xx.208.in-addr.arpa.)
Asking ns1.virt-host.com. for x.xxx.xx.208.in-addr.arpa PTR record: Reports xxxxx.virt-host.com

 

[muddrake]

No, it stops at the ISPs name servers, but I thought maybe that was because when I use dig to check my PTR records, none show up.

 

[phoenixisp]

How many IPs do YOU have?

 

[ShadowMan@]

Originally posted by muddrake
I thought the ISP was supposed to forward RDNS requests to the registered nameserver?

Besides, I've contacted them, and they are saying that it's something on my end. (not that that means anything necessarily)

--
Gary

No, unless you have already made arrangements with the ISP, the rDNS for the IP address (not the domain name) is handled by the ISP.

The PTR records on your server are for DOMAIN name reverse lookups.

The in.addr-arpa reverse entries for the IP address will default to the ISP until you make arrangements with them.

 

[muddrake]

Thanks for the information.

Could you explain what you mean by "The PTR records on your server are for DOMAIN name reverse lookups." though?

 

[jamesyeeoc]

Originally posted by muddrake
No, it stops at the ISPs name servers, but I thought maybe that was because when I use dig to check my PTR records, none show up.

Did you try using their Reverse DNS lookup tool?

http://www.dnsstuff.com/tools/ptr.ch?ip=domain.com

Please report back if that shows it is querying your server, and if it reports you have PTR records.

Also, I think this is what Shadowman was trying to get at by saying it is for domain lookups. You can do a reverse lookup by giving it either a domain name, or an IP address.

 

[muddrake]

Ahh. So, given a domain name, they must just resolve that to the ip first, then do the RDNS lookup.

Yes, I have tried their service, and it does not resolve to the records I have in Plesk (Regardless of how I ask them to do the RDNS lookup). The resolution stops at my ISP, returning one of their systems.

 

[jamesyeeoc]

Yes, if the domain does not resolve to an IP address yet, then any sort of lookup won't work properly. Once the domain resolves to an IP address, hopefully your Plesk server, then try their reverse lookup tool and see what it produces.

 

[muddrake]

It resolves to an IP address just fine, though I did find one incorrect secondary dns server in our records.

The problem though, is that even though I have PTR records listed in plesk for the domain, no PTR entries are being found...

here is the output from 'dnsstuff.com'

Server Response Time
ns01.backupdns.com [199.242.242.199] [Says that there is no PTR record for muddrake.com] 108ms

ns1.muddrake.com [24.106.156.211] [Says that there is no PTR record for muddrake.com] 108ms

 

[ShadowMan@]

Hmm, interesting results. I did a rDNS lookup on 199.242.242.119 and did a browser refresh several times and got this:

Reverse DNS for 199.242.242.199
Generated by [url]www.DNSstuff.com[/url]

Location: United States [City: Helena, Montana]

Preparation:
The  reverse DNS entry for an IP is found by reversing the IP, adding it to "in-addr.arpa", and looking up the PTR record.
So, the reverse DNS entry for 199.242.242.199 is found by looking up the PTR record for
 199.242.242.199.in-addr.arpa.
All DNS requests start by asking the root servers, and they let us know what to do next.
See How Reverse DNS Lookups Work for more information.

How I am searching:
Asking f.root-servers.net for 199.242.242.199.in-addr.arpa PTR record:  
       f.root-servers.net says to go to dill.arin.net. (zone: 199.in-addr.arpa.)
Asking dill.arin.net. for 199.242.242.199.in-addr.arpa PTR record:  
       dill.arin.net [192.35.51.32] says to go to lewis.mt.net. (zone: 242.242.199.in-addr.arpa.)
Asking lewis.mt.net. for 199.242.242.199.in-addr.arpa PTR record:  
       lewis.mt.net [206.127.64.130] says to go to ns02.backupdns.com. (zone: 242.242.199.in-addr.arpa.)

[b]WARNING: Duplicate zone found (242.242.199.in-addr.arpa. is repeated).  This can prevent the lookup from continuing
         (BIND8 and BIND9 will cause a 'server failure' response).  Although I will continue, be aware that
         most DNS servers will not see your reverse DNS entry.[/b]

Asking ns02.backupdns.com. for 199.242.242.199.in-addr.arpa PTR record:  Reports ns01.backupdns.com. [from 209.51.211.159]

Answer:
199.242.242.199 PTR record: ns01.backupdns.com. [TTL 21600s] [A=199.242.242.199]

To see the reverse DNS traversal, to make sure that all DNS servers are reporting the correct results, you can Click Here.

And for the other, it clearly shows that the reverse DNS has NOT been delegated from the ISP to your server:

Reverse DNS for 24.106.156.211
Generated by [url]www.DNSstuff.com[/url]

mail.muddrake.com is not an IP address, so I am using 24.106.156.211 (the A record for mail.muddrake.com).

Location: United States [City: Carmel, Indiana]

Preparation:
The  reverse DNS entry for an IP is found by reversing the IP, adding it to "in-addr.arpa", and looking up the PTR record.
So, the reverse DNS entry for 24.106.156.211 is found by looking up the PTR record for
 211.156.106.24.in-addr.arpa.
All DNS requests start by asking the root servers, and they let us know what to do next.
See How Reverse DNS Lookups Work for more information.

How I am searching:
Asking a.root-servers.net for 211.156.106.24.in-addr.arpa PTR record:  
       a.root-servers.net says to go to figwort.arin.net. (zone: 24.in-addr.arpa.)
Asking figwort.arin.net. for 211.156.106.24.in-addr.arpa PTR record:  
       figwort.arin.net [192.42.93.32] says to go to ns1.biz.rr.com. (zone: 156.106.24.in-addr.arpa.)
[b]Asking ns1.biz.rr.com. for 211.156.106.24.in-addr.arpa PTR record:  Reports rrcs-24-106-156-211.central.biz.rr.com. [from 24.30.200.19][/b]

Answer:
24.106.156.211 PTR record: rrcs-24-106-156-211.central.biz.rr.com. [TTL 3600s] [A=24.106.156.211]

To see the reverse DNS traversal, to make sure that all DNS servers are reporting the correct results, you can Click Here.

If the ISP had delegated the reverse records to your server, then rrcs-24-106-156-211.central.biz.rr.com woul have 'says to go to ns1.muddrake.com, but it does not, so the ISP's in.addr-arpa zone file is still in control!

Hope this helps. (Posted by ShadowMan with jamesyeeoc overseeing)

 

[muddrake]

Thanks, that's what I wanted to know. I wasn't sure if my ISP wasn't forwarding the request because it couldn't find any PTR records, or if it just wasn't setup to do the forwarding.

Much appreciated.