What is a PTR record?

A PTR (pointer) record is a DNS record that maps an IP address to a hostname. It is the reverse of an A or AAAA record and lives in a special zone called in-addr.arpa (IPv4) or ip6.arpa (IPv6).

Why do I need a PTR record?

PTR records are required for many mail servers to pass spam filters. They are also used by network diagnostics tools like traceroute and by some security systems that verify the identity of connecting hosts.

Who controls my PTR record?

PTR records can only be set by the organization that owns the IP address — usually your ISP or cloud provider. You need to request the PTR delegation or update it through your provider's control panel.

How does IPv6 PTR format differ from IPv4?

For IPv4 the octets are simply reversed with dots (e.g. 1.2.0.192.in-addr.arpa). For IPv6 the full 128-bit address is expanded to 32 hex digits, each nibble is separated by a dot, the whole string is reversed, and ".ip6.arpa" is appended.

What is the zone name shown in the result?

The zone name is the part of the PTR name that represents the delegated reverse zone — useful when you need to create or locate the correct zone in your DNS management interface.

PTR Record Generator

Enter an IPv4 or IPv6 address and instantly get the correct PTR record name for your reverse DNS zone.

IP Address Input

IPv4 or IPv6 Address

Quick Examples

Enter an IP address and click Generate PTR

Supports both IPv4 and IPv6

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Summary

A PTR record (pointer record) maps an IP address back to a hostname — the reverse of an A or AAAA record. Setting up correct PTR records is essential for mail server deliverability, network diagnostics, and meeting ISP requirements. This tool computes the exact PTR record name in in-addr.arpa (IPv4) or ip6.arpa (IPv6) format so you can paste it directly into your DNS zone file or control panel.

How it works

Enter an IPv4 address (e.g. 192.0.2.1) or a full IPv6 address (e.g. 2001:db8::1).
The tool validates the address and determines the IP version.
For IPv4, the octets are reversed and ".in-addr.arpa" is appended.
For IPv6, the address is expanded to its full 32-hex-digit form, reversed nibble by nibble, and ".ip6.arpa" is appended.
Copy the PTR record name and the zone name for use in your DNS control panel.

Use cases

Set up rDNS for a mail server to pass SPF/DKIM checks and reduce spam scores.
Verify PTR record format before submitting to your hosting provider or ISP.
Calculate the correct ip6.arpa name for an IPv6 address without manual nibble-reversal.
Troubleshoot reverse DNS mismatches during email deliverability audits.
Provide the PTR name when configuring BIND, PowerDNS, or other authoritative DNS servers.
Learn the difference between in-addr.arpa and ip6.arpa zone delegation.

Frequently Asked Questions

Last updated: 2026-06-13 · Reviewed by Nham Vu