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DNS troubleshooting and common issues

Overview

DNS issues are the most common reason why a website won't load or an email isn't delivered. Because DNS relies on thousands of servers across the globe talking to each other, a single typo or a slow "update period" (propagation) can cause a service to go offline.

This guide helps you identify the symptoms and provides the exact steps to get your domain back on track.


1. Symptom: The domain won't load at all

If you type your domain into a browser and see a "Server Not Found" error, the "address book" of the internet is likely broken.

  • Check the Nameservers: If you registered your domain with DotSync, verify that your nameservers are set to default.
  • External Providers: If you use a third-party (like Cloudflare or GoDaddy) for your DNS, ensure you have an A record pointing to your web host's IP address.
  • The "Trace" Test: Advanced users can run dig +trace yourdomain.com in a terminal to see exactly where the connection is dropping.

2. Symptom: Changes aren't showing (Slow Propagation)

DNS changes do not happen instantly. Every record has a TTL (Time to Live), which tells other computers how long to "remember" the old setting before checking for a new one.

  • High TTL: If your TTL was set to 3600 (1 hour), the rest of the world might not see your change for 60 minutes.
  • The Fix: If you are planning a move, lower your TTL to 300 (5 minutes) at least 24 hours before you make the actual change.
  • Clear Your Cache: Sometimes your own computer is "remembering" the old site. Try opening your site in an Incognito/Private window or use a public tool like DNS Checker to see the global status.

3. Symptom: SSL/Security Certificate Failures

If you see a "Your connection is not private" warning, your SSL certificate is failing to validate.

  • Check Validation Records: Some certificates require a special TXT or CNAME record (often starting with _acme-challenge) to prove you own the domain. Ensure these haven't been deleted.
  • Point to DotSync: If you are using DotSync's automatic SSL, ensure your A or CNAME record is pointing correctly and that the SSL & CDN toggle is turned ON in your dashboard.
  • Wildcard Certificates: If you are trying to secure *.yourdomain.com, you almost always need to use a DNS TXT record for validation.

4. Symptom: Errors with the "Root" Domain

A common technical mistake is trying to use a CNAME for your main domain (example.com). According to official internet rules, this is not allowed and will break your email.

  • The Fix: If a service asks you to "alias" your root domain, use DotSync’s ALIAS record type. This provides the functionality of a CNAME but follows the rules of the internet, keeping your email and website working perfectly.

Technical Toolbox

If you are comfortable with a terminal/command line, use these commands to see what is happening under the hood:

CommandPurpose
dig yourdomain.com +shortQuickly see which IP address your domain is pointing to.
dig yourdomain.com MXCheck if your email records are active.
dig _acme-challenge.yourdomain.com TXTVerify your security certificate's "handshake" record.

When to Contact Support

If you have checked your records and the DNS Checker shows that everything is correct, but your service is still offline, it may be a more complex issue like DNSSEC misconfiguration.

When contacting support, please include:

  1. The specific domain or subdomain (e.g., shop.yourcompany.com).
  2. The record you expect to see (e.g., "It should be pointing to IP 1.2.3.4").
  3. A screenshot of any error message you see in your browser.