This article deals with setting up a subdomain on in DNS. Typically, this is a subdomain that directs to a service other than the domain’s main web hosting. To set up a subdomain on Webhosting, follow the article Webhosting – Subdomains.

In this article, you will learn:

• Why set up subdomains using DNS
• How to set up a subdomain via A and AAAA records
• How to set up a subdomain via a CNAME record
• Common issues
• Frequently asked questions

If you have WEDOS Webhosting and want to run both a domain and subdomains on it, follow the instructions Webhosting – Subdomains.

You typically want to set subdomains via DNS if you run the subdomain on another service (another Webhosting, WebSite, etc.), or with another provider:

• If you are setting up a subdomain for a new WEDOS service, you have the option to check automatic DNS settings in your order. If you do set DNS automatically, follow the instructions in the chapter Subdomain via A and AAAA records.
• For the services of another provider, first obtain their instructions for directing a domain to that service. The instructions will tell you whether to set the subdomain through A or AAAA records, CNAME, or both.

Before setting up subdomains in WEDOS DNS, make sure that the domain really uses our DNS servers (NSSET). Many hosting service provider guides include changing DNS servers. If you are unsure about this change, avoid it. If you change DNS servers, the records kept on the original ones will stop working.

If you know the IPv4 or IPv6 address of the server, you can direct the subdomain using A or AAAA records. You can find these addresses for WEDOS services in the service creation email notification, or in the service detail according to the instructions:

• DNS – A-Type Record 
• DNS – AAAA-Type Record

If you have service addresses ready, go to the DNS Record management interface according to the guide DNS – Domain Records.

Enter the records according to the following table. If your service does not support A or AAAA records, it is ok to enter only one of these types.

Name              TTL    Type  Data
(subdomain-name)  300    A     (IPv4 address)
(subdomain-name)  300    AAAA  (IPv6 address)

Always enter the subdomain name without the domain name. For example, the name www is correct, www.domain.tld is not.

WEDOS does not use CNAME records for its hosting, but many external services do. If you have the choice of entering the subdomain via an A/AAAA or CNAME record, choose one of these options.

A CNAME record disables setting any other records for the subdomain.
The domain or subdomain to which the CNAME record directs must have a valid A or AAAA record.

If you have a domain to which the CNAME record should direct, enter the DNS record administration according to the instructions DNS – Domain Records.

Enter the record according to the following table:

Name              TTL    Typ    Data
(subdomain-name)  300    CNAME  (service-domain)

Common problems with setting up subdomains in DNS include:

• The * record doesn’t work correctly
• Cannot issue certificate for the domain
• The sub.domain.tld doesn’t work

Issue: After adding the record for the subdomain, the * record stopped working.

Cause: If a record of any type (including TXT) exists for any subdomain, all * records, including those of other types, cease to apply to that subdomain.

Solution: Either add the missing records set via the * record to the subdomain, or delete the records that cause the conflict.

Issue: The DNS subdomain cannot be added to the HTTPS certificate, an error message appears:
Failed to add the following domains to Let’s Encrypt certificate:
www.problem.wds-test.eu – Domain DNS records missing.

Cause: By default, subdomains add a subdomain variant with www to the certificate. This tends to be problematic if you are adding a subdomain with its own DNS record.

Solution: Either uncheck the option to add a www variant to each subdomain, or create another record for the version of the subdomain with www.

Issue: The subdomain named sub.domain.tld is not working.

Cause: In the record name, you enter only the name of the subdomain (sub) without the domain name (domain.tld).

Solution: Delete the record named sub.domain.tld and create a new one named sub, copy the rest of the settings from the previous record.

Question: Should I set up a subdomain on the web hosting as well?
Answer: The server the subdomain directs to should be configured to handle the subdomain correctly. With our Webhosting, it is enough that the domain or subdomain is set as the service name, and the subdomain files have been placed in accordance with the Webhosting – Subdomains guide. The WebSite service must be named exactly according to the subdomain (without www).

Question: How do I enable HTTPS on a subdomain?
Answer: Set up HTTPS on the Webhosting. Follow the Webhosting – Subdomains guide.