DNS Lookup Tools

About DNS Lookup Tools

This test will list DNS records for a domain in priority order. The DNS lookup is done directly against the domain's authoritative name server, so changes to DNS Records should show up instantly. By default, the DNS lookup tool will return an IP address if you give it a name (e.g. www.example.com) If you give it an IP address it will return a hostname based on the reverse DNS lookup.

Domain Name System

Domain Name System (DNS) is the system to translate Internet domain and host names to IP addresses or on local networks that use the TCP/IP protocol. DNS automatically changes the names the user types in Web browser address bar to the IP addresses list of Web servers hosting these sites.

DNS implements a distributed database to store website name, address information for all public hosts on the Internet. DNS also assumes IP addressees are stable (rather than dynamically assigned).

For example, when the user types the name of website: www.websitemeta.com/, DNS will understand and convert automatically into the IP address 123.0.8.51. Without DNS, the only way to visit on the Internet is inputting four numbers and dots into web browser to visit the Web site, so it will be more difficult for users to remember all of the IP addresses.

DNS Record

A "zone file" for each domain is configured in DNS server includes “resource records”. In addition, there are several kinds of records like:

Forward DNS and Reverse DNS (A and PTR)

The Address (A) record combines a domain name with an IP address. Beside that, the Pointer (PTR) record is an option to send data for converting DNS that is used for logging domain name and verification process.

Aliasing Names (CNAME)

It is used to create aliases to other names. It is commonly used to map WWW, FTP and MAIL sub-domains to a domain name; for example, a CNAME can combine the sub-domain FTP.WEBSIEMETA.COM with WEBSITEMETA.COM

DNS Name Servers (NS)

The Name Server (NS) record checks the authoritative DNS servers for a domain. It requires a second name server for redundancy, and two Name Server records must be in the zone file (one for the primary and one for the secondary). The secondary server asks the primary server for changes.

Mail Servers (MX)

The Mail Exchange (MX) record checks the server about how many e-mails are directed. It also includes a priority field so that email can be directed to multiple servers in a prescribed order.

Text Record (TXT)

A TXT record would be used for any kind of documentation. It is also used to provide information to the Stateful Packet Firewal (SPF) e-mail authentication system.

First Record in File (SOA)

Start of Authority (SOA) is the first record in “zone file”. It includes the name of primary DNS server, which must correspond to an NS record in the file. The SOA also includes data for the secondary DNS server like the date of last update "Serial Number"