DNS, the Domain Name System, works like the phone book of the internet. It turns a domain name such as example.com into the information computers need, such as an IP address or the mail servers that receive its email.
A DNS lookup asks for that information and shows you the records that are published for the domain. It is the first thing to check when a website does not load, when email is not arriving, or after you change a setting at your DNS provider.
The lookup checks these eight record types at once.
| Type | What it does |
|---|---|
| A | The IPv4 address of the domain. |
| AAAA | The IPv6 address of the domain. |
| MX | The mail servers that receive email for the domain, with a priority number. |
| NS | The name servers responsible for the domain. |
| TXT | Free text, often used for email security (SPF, DKIM, DMARC) and to prove ownership of a domain. |
| CNAME | An alias that points one name to another name. |
| SOA | Administrative details about the DNS zone, such as the primary server and the serial number. |
| CAA | Which certificate authorities are allowed to issue SSL/TLS certificates for the domain. |
A few tips for understanding what you see.
Quick answers about DNS Lookup.
TTL stands for time to live. It tells resolvers how many seconds they may keep an answer before asking again.
A CNAME only exists where a name is an alias. Main domains such as example.com usually have A or AAAA records instead, while subdomains such as www often use a CNAME.
No. DNS Lookup needs a domain name. To find the name linked to an IP address, use Reverse DNS.
Resolvers keep answers until the TTL runs out, and results here are cached briefly. Wait for the old TTL to pass and search again.