5 Tips To Perform DNS Lookup And Troubleshoot DNS

Did you know performing DNS lookups is essential for IT personnel, network administrators, and security specialists? In simple terms, DNS lookup is the querying of the DNS server for information about a domain name, including the IP address associated with it, mail server data, or other DNS records. Therefore, knowing the efficient methods for DNS lookups can help solve connectivity issues, identify network issues, and strengthen cybersecurity habits.

A DNS lookup converts domain names to IP addresses. You perform a DNS query when you enter a URL in a browser, which returns the equivalent IP address. DNS lookups allow the user to retrieve useful information about a domain's DNS records, including the A, MX, CNAME, TXT, and many more.

Here are some tips to help you perform DNS lookup efficiently

1. Perform a DNS lookup using Command-Line Tools

A DNS lookup gives you essential information about a domain's IP address and DNS records. You can look up DNS information and troubleshoot issues with a number of built-in command-line tools.

If you're using Windows, open the Command Prompt and type nslookup. This command returns the domain's corresponding IP address and its authoritative nameserver. To get mail exchange (MX) records, which dictate how emails are routed, you need to use a nslookup. This will show you the mail servers that process the emails for the domain, assisting you in diagnosing email-related DNS problems.

As a Linux and Mac user, you can utilize the dig command to query more specific DNS using dig. This yields more detailed information about the A, MX, and NS records. If you need to query name server records specifically, you can use the dig NS example.com. Utilizing these command-line utilities may assist in identifying whether a domain is resolving properly or having connectivity problems.

2. Check DNS Propagation with Online Tools

When you make DNS updates, such as IP address or name server changes, they are propagated slowly throughout the world. Depending on your domain registrar and your internet service provider (ISP), DNS propagation can take as little as a few minutes to as long as 48 hours.

In order to confirm that the changes have propagated, use online DNS lookup software such as MXToolbox or DNS Tools, which helps you confirm DNS records, MX, A, and CNAME records. Alternatively, you might use Google Admin Toolbox, which provides you with in-depth DNS analysis and DNS troubleshooting. You can maintain uninterrupted website accessibility for your visitors based on their locations by monitoring DNS propagation.

3. Clear DNS Cache to Solve Caching Issues

Sometimes, your system may be experiencing connectivity problems due to corrupted or outdated DNS records cached locally on your system. Clearing the DNS cache removes these records, forcing your system to retrieve new DNS information.

On Windows, you must open the command prompt as administrator and type in ipconfig /flushdns. This removes all the DNS entries that are cached locally, so you receive new records when you visit a site.

On a Mac, in the terminal, type sudo dscacheutil to flush the cache. These steps refresh the DNS resolver and clear out stale records. In addition, as a Linux user, you also need to reboot the Name Service Cache Daemon (NSCD) with sudo systemctl restart nscd. Clearing the DNS cache is particularly useful when websites are inaccessible after DNS changes that were recently made.

4. Correct the Wrong DNS Setup

Misconfigured DNS settings can result in domain resolution errors, rendering the user unable to visit a site. To troubleshoot DNS misconfig, you need first to confirm the nameservers.

To ensure your domain points to the correct nameservers, use dig +short NS example.com. If the output does not show the nameservers your registrar gave, make the necessary configuration changes to your settings accordingly. Second, you need to verify the A record. The A record directs your domain to an IP address. To verify it, use dig +short. This should show the correct IP address allocated to your domain.

You should also verify your connectivity. If you suspect a DNS problem is preventing you from connecting to a site, ping it using ping example.com. If you do not get a response, your domain may not be resolving, indicating a DNS issue. Lastly, you need to verify the DNS settings in the hosting control panel. Most hosting service providers allow you to configure DNS records using a control panel. To prevent accessibility issues, verify that the A, CNAME, MX, and TXT records are set correctly. You can prevent connectivity failures and downtime through correct DNS configuration.

5. Troubleshoot DNS issues using Traceroute and WHOIS lookup

Traceroute can be utilized to identify where the connection breaks on the path to the server if your site becomes slow or unresponsive. You can trace the network problems with the traceroute command. For Windows and Mac/Linux, you can use tracert and traceroute. This utility tracks the path packets take to reach a site and detects delays or failures in the connection.

In addition to that, you also need to perform a WHOIS lookup for domain data. WHOIS lookups display data about a domain's registration data, expiry date, and owner. To perform a WHOIS query, use the WHOIS. An expired or improperly registered domain name leads to site outages. Traceroute and WHOIS queries can troubleshoot network routing issues and confirm domain registration data.

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