Reverse DNS Lookup Online
What is PTR record in DNS?
PTR (from "PoinTeR") - is a reverse DNS record (rDNS), which associate an IP address with domain name. "Reverse" to DNS A record, which associate domain name with IP address.
What is PTR record used for, any examples?
PTR record often used by receiving mail servers as an important part of anti-spam filtration. If you are sending an emails from your own server / domain name and want they will come to "Inbox" folder, not "Spam" / "Junk", you need to have a correct PTR record on your sending IP address - value of PTR must match name of your mail server (which specified in HELO / EHLO).
E.g. you send an emails with "from" address firstname.lastname@example.org from ip address 188.8.131.52, your mail server is mail.yourdomain.com - in this case the PTR record for ip 184.108.40.206 must be exactly mail.yourdomain.com, not a just domain name yourdomain.com how often people think wrongly.
How to make a PTR record?
PTR records can edit only the IP addresses owners, so you just need to contact your server / hosting support and ask them to make a PTR records you need.
Is it possible to make a few PTR records for 1 ip address?
No, it's impossible, there is a strict DNS rule - one ip address can have only one PTR record.
How to know PTR record of ip address?
The easiest way is to use our online tool of course, but there are 2 other ways:
- In Windows:
1. Go to the command prompt mode: "Start" → "Search" → type "cmd" (without quotes) and press the "Enter" key;
2. In command prompt mode type nslookup -type=ptr 220.127.116.11
- In Linux: In command prompt mode type dig -x 18.104.22.168
Don't forget to use an ip address you interests instead of 22.214.171.124 in our examples above.