What is a DNS Lookup?

DNS is the Internet's phonebook. When you type in a website address, your computer asks DNS where to find that site. A DNS lookup is the process by which a DNS record is returned from a DNS server or a request for information about a domain name. 

For example: 

A DNS lookup can be used to resolve an IP address into a hostname. An IP address is just a number that identifies each device on the Internet, which means it's not very useful for humans to read or remember. So instead, we use hostnames—like "google.com"—to access websites.

When you enter a website’s URL in your browser, you’re performing a DNS query request on that domain. A DNS lookup is what happens when your computer asks the Domain Name System (DNS) for the IP address associated with that domain name.

How Does It Work?

When you enter a domain name into your browser (like "google.com"),your computer needs to figure out what IP address corresponds with that domain name so that it can connect you to the correct website. This process begins by looking at its "hosts" file—a list of mappings between hostnames and IP addresses—and seeing if it has any entries for google.com. 

Types of DNS Record Lookups

These are the main types of DNS lookups:

RECURSIVE:

A recursive DNS lookup returns all records associated with the domain name, including any subdomains.

NON-RECURSIVE:

A non-recursive DNS record lookup only returns records for the specified domain name itself.

FORWARD:

Forward lookup, which uses a domain name to find an IP address.

REVERSE:

Finally, the reverse DNS record lookup looks up an IP address in order to find its corresponding domain name

DNS Lookup Usage

NS record Lookup

Checks nameserver (NS) records for your domain.

A DNS NS record is a type of resource record in the Domain Name System (DNS) that identifies a name server responsible for the resolution of queries for a particular hostname. A host may have multiple name servers, and each register an alternative address location for its name server’s responsibility. We will explore the purpose and function of NS records in greater detail below.

MX record Lookup

Checks your DNS MX records (a type of DNS record that you can create to help route emails).  A DNS MX record is a type of DNS record that stores the mail exchange server for a domain. It’s used to route emails to the right place. Every domain name that you own has an MX record associated with it. If you have multiple domains, they all have their own MX records.

Whois Lookup

Whois records are the key to finding out who owns a domain name and where they are located.

Blocklist Lookup

IP blocklisting is a method used to filter out illegitimate or malicious IP addresses from accessing your networks. Blocklists are lists containing ranges of or individual IP addresses that you want to block.

PTR Lookup

Pointer records (PTR records) are one of the records used by the domain name system (DNS),which acts as a directory for the internet. A PTR record contains a hostname that is associated with an IP address. This allows DNS servers to route traffic to the correct location based on the hostname information.

A record Lookup

A records are used to map a hostname (like “example.com”) to an IP address. Your hostname is connected to an IP address by the A Record. A record’s initials stand for address or A. One of the most often used records in the DNS Zones, this one is crucial to the setup of your DNS. The IP address (IPv4) for the provided host is specified in record A.

AAAA record Lookup

AAAA records are used to map a hostname (like “example.com”) to an IPv6 address.

DNS AAAA record or quad A record is a type of DNS record that maps a domain or subdomain to IPv6 (IP address version 6). This directs the browser to land on the right website when someone enters a domain or subdomain in the address bar. 

AAAA record is similar to the A record, except that it lets you specify the IPv6 address of a server instead of IPv4. At present, DNS AAAA records aren’t as popular as A records; however, their usage is soaring rapidly as the adoption of IPv6 is expanding.

TXT record Lookup

A TXT record can be used to add additional information about your domain in a human-readable format. TXT is an acronym for Text. It’s a format used in DNS which allows the data to be stored in a text file and then read back by the computer that needs it. 

TXT records are used to mark up the different types of information stored in DNS. Technically, it’s not a type of record — rather, it’s a structure containing records like the hostname, port number, and IP address of a domain.

CNAME record Lookup

A CNAME record is an alias that points to another web address. A DNS CNAME record maps one hostname to another. This means that you can have multiple hosts with the same IP address, but each with a different name.

For example, a CNAME record can map the alias address www.mydomain.com to the canonical address mydomain.com — where nothing has changed about where visitors go: they are still directed towards whatever destination is specified by the actual A records for mydomain.com (which must be kept up to date).

SOA record Lookup

SOA record or Start of Authority record is a type of DNS record containing crucial information like the administrator’s email address, refreshing server timeframe, domain updating history, etc. Configuring an SOA record in your respective DNS is important to align with the IETF (Internet and Engineering Task Force) standards. 

DNS SOA records are needed for successful zone transfers as you’ve to send them from a primary server to a secondary server.