Administrator of my company allowed me to put my own server in our datacenter and gave me one public address of our AS pool.
I've installed linux and configured basic services. Then i've added A record in DNS server (OVH - where i've bought domain) to map my subdomain to public address of my server.
Everything works good, but now theres last thing to configure - reverse dns. Is there any possible way to make reverse mapping of my IP address to subdomain, if i have only one address of pool and my domain is hosted on outside server (OVH)?
When i have only domain in OVH, i cant add a ptr record.
I can use internal DNS of my company (but only for this one record, I cant move whole domain) if it can help.
Thanks in advance!

  • 5
    dig +trace +add -x ipaddress should help you determine which nameservers hold the reverse dns zone that your IP address is in. That should let you know who to contact (I would guess the answer to that is likely that same admin who gave you the address in the first place). – Håkan Lindqvist Aug 13 '14 at 17:18

You control the domain name, not the IP block. You can assign your domain to any IP you want. The only person able to add a PR record back to your domain (or to any hostname they want) is the admin who controls that IP block. You can do a search online for "whois" and type in the IP to find the owner, or just ask whoever your IT contact is at work.


Yes, it is absolutely possible to set the PTR for that IP address to be anything in the world, including the possibility of setting it to point to your domain.

Yes, you will have to use the company's DNS - there is NO way around this.* Yes, you are also correct that it is only a single record.

However, that single record is NOT part of your domain's zone - rather, it is part of your employer's in-addr.arpa delegation. Your domain happens to point to that IP. The rDNS for that IP will happen to point to your domain, but they are otherwise totally separate things. This is why it does not matter where your domain's DNS happens to be hosted. For Example:

Lets say for sake of argument that your domain is example.com, that the IP is and that your employer's range of IPs is

Your domain's DNS might look something like this:

$TTL 86400 $ORIGIN example.com. @ IN SOA dns.ovh.net. yourname.example.com. 2014081401 10000 2400 604800 3600 @ IN NS ns.ovh.net. @ IN NS ns10.ovh.net. @ IN NS dns.ovh.net. @ IN NS dns10.ovh.net. ; @ IN A you IN A @ IN MX 0 you.example.com. ; www IN A

Notice, no PTR in the above zone file

Now, your employer's DNS might look something like:

$TTL 86400 $ORIGIN 2.0.192.in-addr.arpa. @ IN SOA ns1.yourjob.tld. yourboss.yourjob.tld. 2014081401 10000 2400 604800 3600 @ IN NS ns1.yourjob.tld. @ IN NS ns2.yourjob.tld. ; ; 15 IN PTR you.example.com. ;

Notice, no A records in the above zonefile

In the above two examples, example.com and 2.0.192.in-addr.arpa are two totally separate and unrelated domains that just to happen to each have one single record that happens to point to the other.. Thus too is the relationship between your domain's DNS and your company's reverse DNS.

Hope this helps clarify.

*Even if your workplace were to delegate control to you, it would still involve inserting at least one record into their DNS.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.