NAPTR record stands for Naming Authority Pointer, and it is a type of DNS record that maps domain names to URIs (Uniform Resource Identifiers) and other resources. NAPTR records are most commonly used for applications in Internet telephony - in the mapping of servers and user addresses in the Session Initiation Protocol (SIP).
The combination of NAPTR records with Service Records (SRV) allows the chaining of multiple records to form complex rewrite rules which produce new domain labels or uniform resource identifiers (URIs).
The NAPTR record has the following look in your ClouDNS Control Panel:
| Host | Type: | Points to: | TTL: |
| hostname.com | NAPTR | 1 1 "" "123" "regular" . | 3600 |
NAPTR records are commonly used with SIP in conjunction with SRV records to discover what types of services are available for a name. We can say that the NAPTR record is an extension of the classic records. When someone performs a NAPTR lookup of your domain, he will find out what protocols or ports are implemented, does your domain support SIP or some other VoIP service, and so on.
In order to create a new NAPTR record, go to your DNS zone management page, click on the Add new record link and choose NAPTR. Here are example DNS record settings:
Type: NAPTR
TTL: 1 Hour
Host: example
Order: (from 0 to 65535)
Preference: (from 0 to 65535)
Flag: (empty or U, S, A,P)
Protocol Resolution Service: from 0 to 32 symbols
Regular Expression: someregex
Replacement: somerep
Note: The Regular Expression and the Replacement cannot be used both or left empty.
You can check the NAPTR record for a particular hostname by using one of the following ways:
If you are a Linux/macOS user, you can open the Terminal application and use the DIG command. Here is an example:
$ dig domain.net naptr
If there is an existing NAPTR record for the domain, this command will show it.
If you are a Windows user, or you prefer using an online tool. You can perform the lookup with the ClouDNS Free DNS tool. Simply enter the domain name, and you will view the NAPTR record if one exists.
NAPTR records work with SRV records to provide a two-step resolution process for services in DNS. When a client queries a domain for NAPTR records, these records specify rules for rewriting the domain name and indicate the next step in the resolution process. The NAPTR record includes fields such as Order, Preference, Flags, Service, Regexp, and Replacement, which dictate how the client should modify the domain name and which type of DNS record to query next, typically leading to an SRV record.
After processing the NAPTR record and rewriting the domain name, the client performs a DNS query for SRV records using the new domain name. SRV records contain information about the target service, including the hostname, port, priority, and weight, which guide the client to the appropriate server for the requested service. This method allows for flexible and scalable service discovery, load balancing, and failover, particularly useful in complex environments like SIP (Session Initiation Protocol) where services need to be dynamically and efficiently resolved.
Question: Does NAPTR work in the same manner as the PTR record?
Answer: No, they are not the same. PTR records are used for Reverse DNS Resolution. And NAPTR records are mostly used for SIP communication.
Question: Is a NAPTR record required for every domain name?
Answer: No, it is not required for every domain name.
Question: Can I have multiple NAPTR records for a single domain name?
Answer: Yes, you can have several NAPTR records for a one domain name.