You can use this tool to check the DNS records of any given domain name.
How does this tool work?
Simply enter a domain name in the form above and click the
Lookup button to query the DNS records for the given domain.
- Select Default to use query our default name servers - This will use Google's Public DNS servers,
126.96.36.199, for your query.
- Using Authoritative will query the name servers for a given domain (ie, example.com) and use those for the lookup (ie, ns1.example.com, ns2.example.com)
- The Custom option allows you to specify which DNS server(s) to query for the given domain.
What is DNS?
DNS, or the Domain Name System, is a database of information for network resources - kind of like the phonebook of the internet.
Information in DNS is stored in a list of resource records related to a domain name. Each DNS resource record has a type, a TTL (Time to Live or expiration time), a class, and type-specific data.
The most common types of DNS records you'll see are likely A, NS, CNAME, MX and TXT. We also have a longer list of all available DNS record types for the keen observer.
- A type records point a domain name (example.com) to the IP address (or addresses) of its servers on the internet.
- NS, or Name Server, records tell DNS servers on the internet which DNS servers are authoritative for your domain, in order to query them for your domain's DNS records if they aren't already cached.
- CNAME records are basically aliases (or, Canonical Names). This type is used to reference one resource record from another.
One of the most common usages of CNAME records is to say that
www.example.comis at the same address as
example.comby adding a
www IN CNAME @or similar record.
- MX, or Mail Exchange, records tell email servers on the internet where to direct mail for a given domain name.
An interesting "quirk" of MX records is the
priorityfield which is used to build fault tolerance and high uptime to the email protocol, but which has also been exploited by spam email hosts in the past in poorly configured mail networks.
- TXT records allow you to store arbitrary textual information in DNS records. This type of record is commonly used for defining SPF or DKIM rules for a domain (for use with email servers), and for site verification or tracking services among other things (think Google Analytics and similar services).
- An SOA type record is the only required record for a DNS zone. It contains authoritative information about a DNS zone, including the primary name server, the email of the domain administrator, the domain serial number, and several timers relating to refreshing the zone.
A records Time to Live or TTL advises how long a given response is valid (and can thus be cached, or remembered, to improve response times and fault-tolerance of the internet in general) before another request should be made for the same domain/record type.
So, what does it all really mean?
Basically, DNS lets your computer turn 'google.com' into an IP address (something like 188.8.131.52) so that your web browser can find the websites you request on the internet. DNS is also used to help direct emails to the correct mailboxes, fight spam, block ads and all other manner of things.