A 404 error is one of the most common HTTP status codes users encounter when browsing the internet. It indicates that the requested page could not be found on the server. While 404 errors are typically linked to incorrect URLs, missing pages, or server-side issues, they can also occur as a result of DNS (Domain Name System) misconfigurations. DNS is crucial for resolving domain names into IP addresses, and if the DNS records are incorrect or improperly configured, it can result in users being unable to access specific pages or even entire websites.This article will explore how to troubleshoot 404 errors due to DNS issues, why DNS misconfigurations lead to 404 errors, and what steps you can take to resolve them. Whether you're a website owner, an IT professional, or a developer, understanding DNS and how it interacts with web requests is key to resolving these errors and keeping your site running smoothly.

Understanding 404 Errors and Their Causes

A 404 Not Found error occurs when a user’s browser makes an HTTP request for a page that doesn’t exist or can’t be located on the server. It’s often displayed with a message like: "404 - Page Not Found" or "Sorry, this page could not be found." The most common reasons for a 404 error include:

1. Mistyped URL: The URL entered by the user doesn’t match any known page on the website.
2. Deleted or Moved Content: The requested page may have been deleted or moved without updating the relevant links.
3. Broken Links: External or internal links pointing to a non-existent page result in a 404 error.

However, 404 errors can also be triggered by DNS issues, where the domain fails to resolve correctly to the right web server, causing the requested page to be unreachable even if the page exists.

How DNS Issues Cause 404 Errors

DNS acts as a bridge between human-readable domain names (e.g., www.example.com) and machine-readable IP addresses (e.g., 192.0.2.1). When you type a domain name into your browser, your device sends a request to a DNS server to resolve the domain to an IP address, and then it makes a request to that server for the page.If there's an issue with DNS resolution, it can prevent users from reaching your website or specific pages on it, leading to 404 errors. Here are some DNS-related issues that may cause 404 errors:

Incorrect DNS Records

If DNS records for your domain (such as A records, CNAME records, or MX records) are misconfigured, the browser may be directed to the wrong server or unable to resolve the domain at all. This would result in a failure to locate the requested page, triggering a 404 error.

Expired DNS Records

DNS records are associated with specific time frames known as TTL (Time To Live). If a DNS record expires or isn’t refreshed, the server might still try to route users to outdated or incorrect IP addresses, leading to 404 errors.

DNS Server Outages

If the DNS provider you’re using is down or experiencing issues, users won’t be able to resolve your domain correctly, resulting in 404 errors. This typically occurs if you're using external DNS servers that are unreliable.

DNS Propagation Delays

When DNS changes are made (e.g., when switching web hosts or updating records), it can take 24 to 48 hours for the changes to propagate across all DNS servers globally. During this time, some users may encounter 404 errors because they are still directed to outdated IP addresses.

Incorrect Subdomain Setup

If you’re trying to access a subdomain (e.g., blog.example.com), but the DNS records are incorrectly configured, it might result in a 404 error because the subdomain doesn’t exist from the DNS perspective.

Troubleshooting 404 Errors Due to DNS Issues

If you’re encountering 404 errors that appear to be related to DNS issues, follow these steps to diagnose and fix the problem:

Verify DNS Records

The first step in troubleshooting DNS-related 404 errors is to verify that your DNS records are correctly set up. Here’s how to check your DNS configuration:

1. Log in to your DNS provider: Go to your domain registrar or DNS hosting provider’s control panel (e.g., GoDaddy, Namecheap, Cloudflare).
2. Check A Records and CNAME Records:
   • The A record should point to your web server’s IP address. If you’ve changed web hosts recently, this is the most likely place to look.
   • The CNAME record should correctly point subdomains (e.g., www.example.com) to your root domain or other relevant domain.
   • If your website relies on a specific subdomain (like www.example.com), make sure it has the appropriate CNAME or A record.
3. Verify TTL Settings: Ensure that your TTL is set appropriately. A low TTL (e.g., 300 seconds) is useful when making frequent changes to DNS records, but too high of a TTL can result in outdated caching and cause issues with DNS resolution.

How to Check DNS Records:

You can use online tools such as DNS Checker, MXToolbox, or WhatsMyDNS to verify if your DNS records are properly set up and propagated across the world. Enter your domain name and check if the A records, CNAME records, and other DNS records are returning the correct values.

 Flush DNS Cache

Sometimes, your browser or operating system may cache outdated DNS information, leading to 404 errors even if the DNS records have been updated. To solve this, you can flush the DNS cache on your device.

• For Windows:

  1. Open Command Prompt as an administrator.
  2. Type ipconfig /flushdns and hit Enter.
  3. This clears your DNS cache.

• For macOS:

  1. Open Terminal.
  2. Type sudo killall -HUP mDNSResponder and hit Enter.
  3. Enter your admin password if prompted.
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 Check for DNS Propagation Issues

When you make changes to your DNS records, it can take up to 48 hours for those changes to fully propagate across all DNS servers. During this period, some users might be directed to the old IP address, causing 404 errors.

To check DNS propagation, you can use tools like DNS Propagation Checker or WhatsMyDNS. These tools will show you how far your DNS changes have propagated around the world.

What to do if DNS Propagation is the Issue:

• Wait up to 48 hours for DNS changes to fully propagate.
• If the issue is urgent, you can try changing your TTL to a lower value before making DNS changes so that the propagation occurs faster.

 Test for DNS Server Outages

If your website is still returning 404 errors despite correctly configured DNS records and proper DNS propagation, the issue could be with the DNS server itself.

• Check DNS provider status: Visit your DNS provider’s status page or contact their support team to see if there are any outages or issues affecting DNS resolution.
• Use a different DNS provider: If your DNS provider is unreliable, you may want to consider switching to a more reliable service, such as Google Public DNS (8.8.8.8, 8.8.4.4) or Cloudflare DNS (1.1.1.1). Changing DNS servers can often resolve DNS-related 404 errors.

Verify Web Hosting Configuration

In some cases, the DNS records may be correct, but the issue lies with your web hosting server or content management system (CMS). If your DNS records are pointing to the correct server, but the requested page returns a 404 error, it could be due to:

1. Missing or Deleted Pages: Double-check your server or CMS to ensure that the requested page exists.
2. Server-Side Issues: If your website is hosted on a platform like WordPress, Joomla, or any other CMS, check the configuration of your website’s permalinks or URL routing. Sometimes a misconfiguration of these settings can cause valid URLs to return 404 errors.

Steps to Take:

• Check server logs: Review your web server’s error logs to identify any misconfigurations that could be causing 404 errors.
• Ensure correct file paths: Make sure that the requested page exists on the server and that the URL structure is configured correctly.
• Review CMS settings: If using a CMS, check if any permalink settings have been altered or broken.

 Test with a Different Device or Browser

Sometimes, the issue may be related to local network configurations, DNS settings, or a specific browser. If you are encountering 404 errors, try testing your website on different devices, networks, or browsers to rule out device-specific issues.

Usage Field for Troubleshooting 404 Errors Due to DNS Issues

The process of troubleshooting 404 errors due to DNS issues is important for businesses, web developers, IT teams, and individuals who manage websites, online services, and web applications. Understanding the underlying causes of DNS-related 404 errors and how to resolve them is crucial for maintaining a stable and accessible web presence. Here are some usage fields where this issue commonly arises:

1. Website Administrators and Owners

   • Purpose: Website owners and admins may face 404 errors due to DNS issues affecting their website’s availability.
   • Impact: It can lead to downtime, affecting site traffic, user experience, and revenue, especially for e-commerce or service-based websites.

2. Content Management Systems (CMS) Users

   • Purpose: Websites built on CMS platforms like WordPress, Joomla, or Drupal can experience 404 errors when DNS records are misconfigured.
   • Impact: Users may not be able to access certain pages, causing frustration among visitors or potential customers.

3. Web Hosting Providers

   • Purpose: Hosting companies need to diagnose and resolve DNS-related 404 errors for their clients.
   • Impact: A hosting provider’s inability to resolve DNS issues can affect client satisfaction and site performance, leading to customer churn.

4. E-commerce Websites

   • Purpose: For e-commerce websites, 404 errors due to DNS issues can disrupt customer access to products and checkout pages.
   • Impact: This directly affects sales and user trust, which are crucial in an online store environment.

5. SEO and Marketing Professionals

   • Purpose: SEO and marketing specialists need to ensure that their websites remain accessible to avoid the negative impact on search engine rankings.
   • Impact: Search engines like Google may penalize websites that frequently return 404 errors, hurting their visibility in search results.

6. Website Developers

   • Purpose: Developers who manage domain names, servers, and website configurations need to identify DNS-related issues causing 404 errors.
   • Impact: This ensures that the site runs smoothly and prevents unnecessary downtime or errors for end users.

7. Corporate Websites

   • Purpose: Companies with internal or external-facing websites may experience 404 errors due to DNS misconfigurations.
   • Impact: It can affect employee access to internal tools, or external stakeholders’ access to resources and information.

8. Education Platforms

   • Purpose: Schools and online learning platforms that rely on web-based tools need to address DNS-related 404 errors to ensure students can access their materials.
   • Impact: This can hinder educational delivery and frustrate students, especially if access to important pages or resources is blocked.

9. Web Services and APIs

   • Purpose: Developers or businesses providing web-based APIs need to ensure that their DNS settings are correctly configured to avoid 404 errors when users try to access their services.
   • Impact: API users may experience broken integrations or errors in accessing services due to DNS misconfigurations.

10. Nonprofits and Community Websites

    • Purpose: Nonprofits depend on their websites to engage with visitors, donors, and volunteers. DNS issues leading to 404 errors can disrupt communication and donations.
    • Impact: A lack of accessibility can hinder fundraising efforts or outreach campaigns.

Technical Issues in Troubleshooting 404 Errors Due to DNS Issues

Incorrect DNS Records

• Issue: Incorrectly configured DNS records, such as A records or CNAME records, can lead to requests being directed to an incorrect server, resulting in a 404 error.
• Solution: Check the DNS records to ensure they are pointing to the correct IP address or domain.

1. Outdated DNS Cache

   • Issue: The DNS cache in the browser, operating system, or server can retain old DNS information, leading users to a non-existent server.
   • Solution: Clear DNS caches on the server, browser, and local machine.

2. DNS Propagation Delays

   • Issue: When DNS changes are made (e.g., changing your hosting provider), they may take 24 to 48 hours to propagate, causing some users to encounter 404 errors due to outdated records.
   • Solution: Wait for full DNS propagation or check DNS propagation status using tools.

3. Expired DNS Records

   • Issue: DNS records may expire if the TTL (Time To Live) is not set correctly, causing the browser or DNS resolver to fail to resolve the correct IP address.
   • Solution: Update or renew expired DNS records to avoid access issues.

4. Server Downtime or DNS Server Outages

   • Issue: A DNS server might be down, preventing users from resolving your domain to the correct IP address and resulting in 404 errors.
   • Solution: Verify the DNS server’s status with your DNS provider, and switch to a different DNS server if necessary.

5. Misconfigured Subdomains

   • Issue: If you use subdomains (e.g., blog.example.com), incorrect or missing CNAME records can cause 404 errors on subdomains.
   • Solution: Ensure the correct CNAME or A record is set for subdomains.

6. Incorrectly Configured Nameservers

   • Issue: If the nameservers are not pointing to the correct DNS provider, DNS queries will fail, leading to 404 errors.
   • Solution: Update your nameservers to the correct ones provided by your hosting or DNS service provider.

7. DNS Zone File Misconfigurations

   • Issue: A misconfigured DNS zone file can cause issues with resolving the domain name to the correct server.
   • Solution: Ensure the zone file is correctly configured with the right record types and IP addresses.

8. Misconfigured Web Server Settings

   • Issue: Even if DNS records are correctly set up, web server configuration issues (e.g., Apache or Nginx misconfigurations) may lead to 404 errors.
   • Solution: Review web server logs and configurations for issues.

9. Domain Transfer Issues

• Issue: If you recently transferred your domain or hosting provider, there may be lingering issues with DNS settings during the transfer process.
• Solution: Ensure that the DNS records were fully updated and propagated post-transfer.

Technical FAQ for Troubleshooting 404 Errors Due to DNS Issues

What causes a 404 error related to DNS?

• Answer: A 404 error related to DNS typically occurs when the domain fails to resolve to the correct web server due to issues like incorrect DNS records, outdated DNS cache, or DNS server outages.

 How do I check if my DNS records are correct?

• Answer: You can use tools like DNS Checker, MXToolbox, or WhatsMyDNS to verify if your DNS records are pointing to the correct IP address and are propagating properly.

 How long does it take for DNS changes to propagate?

• Answer: DNS changes usually take 24 to 48 hours to fully propagate across the internet, though some updates may happen faster or slower depending on TTL settings and DNS provider.

How can I clear the DNS cache to fix a 404 error?

• Answer: On Windows, use ipconfig /flushdns in the Command Prompt. On macOS, use sudo killall -HUP mDNSResponder in Terminal. On Linux, run sudo systemd-resolve --flush-caches in the command line.

 How can I fix a 404 error caused by an expired DNS record?

• Answer: You can fix expired DNS records by logging into your DNS provider’s control panel and renewing or updating the expired record with the correct IP address.

 Why is my subdomain giving a 404 error?

• Answer: A 404 error on a subdomain could be caused by missing or incorrect CNAME or A records. Verify the DNS configuration for the subdomain and ensure it points to the correct server.

 How can I test if a DNS server is causing a 404 error?

• Answer: Use tools like Pingdom, DNSstuff, or Traceroute to test the response from your DNS server and check if the server is reachable. You can also change your DNS server settings to use Google DNS or Cloudflare DNS to rule out issues with your DNS provider.

How do I check if the DNS zone file is configured properly?

• Answer: To check the DNS zone file, log in to your domain registrar or DNS provider's control panel and ensure that the A records, CNAME records, and other necessary entries are correct.

 What can I do if my DNS provider is experiencing an outage?

• Answer: Contact your DNS provider for support. You can also switch to a more reliable DNS provider (e.g., Cloudflare or Google DNS) temporarily to avoid prolonged issues.

 How can I prevent DNS issues from causing future 404 errors?

• Answer: Regularly check your DNS records for accuracy, set a low TTL for frequently updated records, use reliable DNS services, and ensure your DNS settings are properly configured whenever making changes to your website or hosting provider.