What is an NS record?
An NS record or name server record identify which name servers are authoritative for a zone. DNS resolvers will query the servers listed in the NS records of a domain name for specific DNS records such as A, AAAA, MX, TXT. A DNS zone must contain at least one NS record but you can have as many NS records as you would like for your domain name. The benefit of having multiple NS records is the redundancy of your DNS service.
In order to have a valid DNS configuration, the NS records configured in the DNS zone must be exactly the same as these configured as name servers at your domain name provider.
NS record format
A typical NS record looks like the following in standard BIND format:
$ORIGIN example.com. @ 3600 IN NS ns1.dynu.com. @ 3600 IN NS ns2.dynu.com. @ 3600 IN NS ns3.dynu.com. @ 3600 IN NS ns4.dynu.com. @ 3600 IN NS ns5.dynu.com. @ 3600 IN NS ns6.dynu.com.An anatomy of the NS Record
@ 3600 IN NS ns1.dynu.com.looks like the below:
|Host Label||TTL||Record Class||Record Type||Name Server|
It defines the hostname of a record and whether the hostname will be appended to the label. Fully qualified hostnames terminated by a period will not append the origin.
The time-to-live in seconds. It specifies how long a resolver is supposed to cache or remember the DNS query before the query expires and a new one needs to be done.
Mainly 3 classes of DNS records exist:
- IN (Internet) – default and generally what internet uses.
- CH (Chaosnet) – used for querying DNS server versions.
- HS (Hesiod) – uses DNS functionality to provide access to databases of information that change infrequently.
The record format is defined using this field. Common record types are A, AAAA, CNAME, CAA, TXT etc. In the case of an NS record, the record type is NS.
Name Server Host
The hostname of the name server. The hostname cannot point to a CNAME record.
How to add an NS record?
For instructions on how to add an NS record with us, you may refer to the tutorial here.
NS record glossary
Authoritative Name Server
An authoritative Name Server is a nameserver (DNS Server) that holds the actual DNS records (A, AAAA, TXT, etc) for a particular domain/ address. Authoritative Name Servers need to be set up at the domain registrar and they only respond to DNS queries for the domain names that they host.
DNS Recursive Resolver
A DNS server that queries an authoritative nameserver to resolve a domain/ address.
Berkeley Internet Name Daemon - is the most commonly used DNS software on the Internet and Dynu observes BIND format.