DNS - Troubleshooting

In this article, you will learn:

• How to find the cause of a DNS issue
• How to solve DNS issues:
  • Servers
  • Records in general
  • Records pointing to the web
  • Records pointing to mail
• Frequently asked questions

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DNS Issue Diagnostics

Nonfunctional or incorrectly configured DNS may manifest as an unavailable domain, that is, a browser message about the website being unavailable with the code DNS_PROBE_FINISHED_NXDOMAIN. Alternatively, the website may display old content or web hosting provider errors (for example, a suspended or deleted service), emails may not be delivered, etc.

For system diagnostics of the domain, you can use a tool in the customer administration. Instructions can be found in the article Domains – Diagnostics.

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DNS Troubleshooting

DNS issues fall into two categories: either it is incorrect configuration of DNS servers, from which domains obtain data for proper functioning, or DNS records (usually records pointing the domain to the web or emails).

DNS servers

Common DNS server issues include:

• Unavailable DNS servers. This is usually a problem with the domain and its configuration, which is covered in the article Domains – Troubleshooting.
• DNS server changes in progress. Propagation of the configured DNS server changes across the internet is relatively slow, typically 6 – 48 hours. To avoid inconsistent behavior or service outages during this time, make sure identical DNS records are set on both sets of DNS servers. During the change process, turn off DNSSEC.
• Record changes on the wrong DNS servers. If the configured records are not propagated even after dozens of minutes, make sure you are making the changes with the correct provider. WEDOS DNS records have no effect on the functionality of a domain that uses another provider’s DNS servers.

DNS records

Common issues with DNS records in general include:

• Time needed for record propagation. For WEDOS DNS records, allow about 30 minutes for propagation with a TTL value of 300. For higher TTL values, propagation may take longer.
• Incorrect record name. Different DNS service providers enter records in different ways. When entering record names in WEDOS DNS, avoid entering the @ character (instead, leave the Name field empty) and the domain itself (the system will fill in the main domain name automatically).
• Subdomain conflict. If you rely on subdomain routing using a record named *, make sure that no other records conflict with this routing. Subdomains for which a specific record of any type exists do not use the * record. Set all routing for such subdomains directly.
• Incompatible record settings. The system warns about incorrect or incompatible record settings before saving a new record or change. Solve the issue according to the instructions in the error message.

Website DNS records

The website is handled by DNS record types A, AAAA, CNAME and ALIAS. Common issues with DNS configuration for a website include:

• Insufficient DNS records configured. When entering or changing DNS records, make sure you are really entering all the records required by your web hosting provider. Typically, these are records for the main domain (A, AAAA, ALIAS) and all subdomains (name *) or at least the www subdomain.
• AAAA records from an older service. When migrating to web hosting that uses only A records, delete all AAAA records with the same names as the modified A records.

Email DNS records

For emails to work properly, it is especially important to configure MX records correctly, and also DKIM and SPF. Common issues with DNS configuration for emails include:

• MX records with a name. MX records are usually entered for the main domain (@domena.tld), so leave the Name field empty.
• MX records from different providers. If you are changing MX records to another provider, delete all remaining records from the original provider.
• Incorrect SPF record. Make sure you have exactly one SPF record. If you need to enter SPF records for multiple email service providers, combine them all into one according to the instructions in Emails – SPF record.

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Frequently asked questions