DNS problems can prevent websites from loading, stop email from being delivered, or cause services to point to the wrong server. DNS, or Domain Name System, acts like the internet's address book by translating domain names into the IP addresses computers use to connect. When DNS is not working correctly, the issue may affect one device, one network, or the domain's public records.
This article explains common DNS issues, how to identify where the problem is occurring, and the steps you can take to resolve it. It is intended as a practical reference for Apexhost customers managing domains, websites, email, or related services.
What DNS troubleshooting involves
DNS troubleshooting is the process of checking whether a domain name is resolving correctly and whether the published DNS records match the service you are trying to use.
Common DNS-related symptoms include:
* A website shows a server not found or DNS error message
* A domain points to an old hosting account or incorrect IP address
* Email is not being received after changing MX records
* DNS changes appear to work for some users but not others
* A subdomain does not load even though the main domain works
* Verification records for Microsoft 365, Google Workspace, or other services are not being detected
DNS issues often fall into one of these categories:
* The domain has the wrong nameservers
* The DNS zone is missing required records
* A record contains an incorrect value
* Recent changes have not fully propagated yet
* A local device or network is using cached DNS results
* DNSSEC or third-party DNS settings are incorrect
Before you begin
Before troubleshooting DNS, make sure you have the following information available:
* The full domain name
* The service you are trying to use, such as website hosting, email, or a subdomain
* The expected destination, such as a server IP address, hostname, or mail provider
* Access to your domain registrar or DNS hosting provider
* The approximate time when DNS changes were made, if relevant
It is also important to confirm where DNS is hosted. In some cases, the domain registrar manages the nameservers while the DNS zone is hosted elsewhere.
How to troubleshoot DNS issues
1. Check whether the domain has expired
If a domain has expired, DNS resolution may stop working entirely or behave unpredictably depending on the registrar's policies. Confirm that the domain is active and renewed.
2. Confirm the nameservers in use
The nameservers determine which DNS provider is authoritative for the domain. If the domain is using different nameservers than expected, changes made in the wrong DNS zone will have no effect.
Check whether the nameservers match the provider where you are editing records.
3. Verify the DNS records
Review the key records needed for the service:
* A record for the root domain or subdomain
* CNAME record where an alias is required
* MX records for mail delivery
* TXT records for SPF, DKIM, DMARC, or domain verification
* NS records for delegated subdomains where applicable
Make sure each record has the correct host, type, value, and intended destination.
4. Check for propagation delay
After DNS changes are made, it can take time for the new records to be seen across different networks. This is commonly referred to as DNS propagation. Some users may see the new destination while others still receive the old result until cached data expires.
5. Clear local DNS cache
Your computer or router may still be using older DNS information. Flushing the local DNS cache or testing from a different network can help confirm whether the issue is local or public.
6. Test from multiple locations
If the domain works on mobile data but not on office Wi-Fi, the issue may be with local caching or the network's resolver. If the result is wrong everywhere, the problem is more likely in the domain's public DNS records.
7. Confirm the service itself is ready
Sometimes DNS is correct, but the website, mail server, or application at the destination is not configured yet. For example, a domain may point to the right server IP address, but the hosting account may not yet be added to the server.
Common DNS issues and how to fix them
Website does not load
If a website fails to load, check the A record or CNAME record for the domain and confirm it points to the correct hosting service.
Possible causes include:
* The domain points to an old server
* The nameservers were changed but the new DNS zone is incomplete
* The hosting account is not configured for the domain
* A recent DNS update has not propagated yet
To resolve this:
1. Confirm the correct IP address or hostname with your hosting provider.
2. Check the active nameservers for the domain.
3. Update the A record or CNAME record if needed.
4. Wait for propagation if a recent change was made.
Email is not working
If email is failing, the issue is often related to MX records, but SPF, DKIM, and DMARC TXT records may also need to be checked.
Possible causes include:
* MX records point to the wrong mail provider
* Old MX records were not removed during migration
* Mail security records are missing or incorrect
* Autodiscover or related CNAME records are missing for Microsoft 365 or similar services
To resolve this:
1. Confirm the correct MX and TXT records for your email provider.
2. Remove outdated or conflicting records where appropriate.
3. Recheck the DNS zone after saving the changes.
4. Allow time for the updated records to propagate.
DNS changes are not visible yet
This is one of the most common DNS concerns. DNS updates are not always immediate because internet service providers, devices, and browsers may store cached results for a period of time.
To check this:
* Test from another device or network
* Use a public DNS lookup tool to see the current authoritative records
* Restart your router if your network appears to be using stale results
If the authoritative DNS records are correct, the issue may simply be propagation or caching.
Subdomain is not working
If a subdomain such as blog.example.com or mail.example.com does not work, review the specific record for that host.
Common causes include:
* The host name was entered incorrectly
* The subdomain record was created in the wrong DNS zone
* There is a conflicting A record and CNAME record for the same host
* The destination service is not configured for the subdomain
Make sure the subdomain has only the required record type and that the target value is correct.
Third-party verification fails
Services such as Microsoft 365, Google Workspace, and other platforms often require a TXT or CNAME record to verify domain ownership.
If verification fails:
* Confirm the record was added to the correct DNS host
* Check that the value matches exactly, including punctuation
* Make sure the domain is using the nameservers you expect
* Wait for propagation before retrying verification
Even a small typing error can prevent verification from succeeding.
Best practices for DNS management
* Keep a record of any DNS changes you make
* Confirm whether DNS is hosted with your registrar, hosting provider, or a third-party DNS service before making edits
* Avoid making multiple unrelated DNS changes at the same time when troubleshooting
* Remove outdated records when migrating services, but only after confirming they are no longer required
* Double-check record names and values before saving
* Understand that TTL settings influence how long cached records may remain in use
For important services such as email, careful DNS management helps prevent downtime, missed messages, and service interruptions.
Troubleshooting checklist
Use this checklist when diagnosing a DNS issue:
* Confirm the domain is active and not expired
* Check the active nameservers
* Identify where DNS is actually hosted
* Verify the relevant A, CNAME, MX, or TXT records
* Confirm the record values with your service provider
* Test from another network or device
* Clear local DNS cache if needed
* Allow time for propagation after recent changes
* Confirm the destination service is configured and online
Frequently Asked Questions
How long do DNS changes take to update?
DNS changes can begin appearing quickly, but full propagation may take up to 24 to 48 hours depending on caching, TTL values, and the networks involved.
Why does my website work on one network but not another?
This usually indicates DNS caching. One network may still be using an older DNS result while another has already refreshed.
Can I update DNS records if my domain uses third-party nameservers?
Yes, but you must make the changes wherever the active nameservers are hosting the DNS zone. Updating records in an inactive zone will not affect live DNS.
What is the difference between nameservers and DNS records?
Nameservers define which system is authoritative for the domain's DNS. DNS records are the individual entries within that system, such as A, MX, CNAME, and TXT records.
Related Articles
* What is DNS?
* DNS Propagation Explained
* How to Change Nameservers
* Understanding A, CNAME, MX and TXT Records
* Troubleshooting Email Delivery Issues
* Microsoft 365 DNS Setup
* Google Workspace DNS Setup
Need More Help?
If you require further assistance, please contact Apexhost Support at support@apexhost.com.au.
