The DNS domain name system is the address book of the Internet, converting domain names into IP addresses. Domain names are unique alphanumeric addresses that users enter in the URL bar of a browser to access a website. Sometimes a DNS configuration error can cause a website access failure. Here are some common tools you can use to troubleshoot DNS problems.

Nslookup is an old command-line tool that can lookup and provide details about Internet nameservers. For example, the mapping between domain names and IP addresses. Query DNS records for linuxtechwhiz.info:

$ nslookup linuxtechwhiz.info

The output displays the IP address corresponding to the server information and domain name.

MXToolBox is an online tool that provides free and paid network diagnostics and DNS query tools. It provides a comprehensive overview of domain name health, including monitoring domain names, displaying DNS or IP blacklist information, checking mail server issues, checking Web servers, and running more than 15 tests on DNS servers.

Dig is a domain name information collector that can query complex details of many types of DNS records. More detailed than nslookup (including A, MX, and SOA records) :

$ dig linuxtechwhiz.info

To display the IP address mapping, use the +short suffix:

$ dig linuxtechwhiz.info +short

The host command is used for manual DNS resolution and can perform forward and reverse lookups, as well as query SOA and MX records. For example, forward lookup:

$ host linuxtechwhiz.info

Reverse lookup:

$host 173.82.232.55

Query SOA records:

$ host -C linuxtechwhiz.info

To query MX records:

$ host -t mx google.com

The ping command is used to check the reachability of the system. You can ping the domain name to test whether DNS resolution is normal.

$ ping linuxtechwhiz.info -c 4

A normal response indicates that DNS resolution is working properly. An error may indicate a DNS resolution problem.

IntoDNS is a tool for checking and troubleshooting DNS problems that quickly generates detailed reports on NS records, name servers, SOA and MX records, TTL, refresh intervals, etc., and provides mail server IP addresses and their validity information.

These tools provide insight into DNS records and help troubleshoot faults or errors related to domain names. I hope you found this article helpful. Any comments or feedback are welcome.

Among the above tools, ping, nslookup, nslookup, and host commands are very suitable for beginners to use, and relatively intuitive operations do not require too many technical operations. Beginners can also try more complex tools such as dig if they are willing to learn.