This article deals with setting up a subdomain on a domain (in DNS). Typically, this is a subdomain that points to a service other than the Webhosting domain. To set up a subdomain on a webhost, follow the instructions in Webhosting - Subdomains.
In this article you will learn:
- Why set up subdomains in DNS
- How to set up a subdomain via A and AAAA records
- How to set up a subdomain via a CNAME record
- Common problems
- Frequently Asked Questions
Subdomains in DNS
If you have a VEDOS Webhosting and want to run both a domain and subdomains on it, follow the instructions Webhosting - Subdomains.
Subdomain settings in DNS are especially useful if you run the subdomain on another service (second Webhosting, WebSite, ...) or with another provider:
- If you are setting up a subdomain for a new WEDOS service, you have the option to check the automatic DNS settings in the order. If you do not have DNS set up automatically, follow the instructions in the Subdomain via A and AAAA records chapter.
- For services from another provider, first provide instructions for pointing the domain to that service. The instructions will tell you whether to set up the subdomain via A (or AAAA) records, CNAME, or both.
Before setting up subdomains in DNS WEDOS, make sure that the domain is actually using our DNS servers (NSSET). Many hosting provider manuals 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.
Subdomain via A and AAAA records
If you know the IPv4 or IPv6 address of the server, you can direct the subdomain by using A or AAAA records. To obtain these addresses for VEDOS services, refer to the setup email or the service details in the DNS - Type A and AAAA records guide.
If you have service addresses ready, enter DNS records administration by following the instructions in DNS - Domain Records.
Enter the entries according to the following scheme. If your A or AAAA service does not support records, you can enter only one of these types.
Name TTL Type Data
(name-subdomains) 300 A (IPv4 server address)
(name-subdomains) 300 AAAA (IPv6 server address)
Always enter the subdomain name separately without the domain name. For example, the name www is correct, www.domena.tld is not.
Subdomain via CNAME record
VEDOS does not use CNAME records for its hosting, but many external services do. If you have the choice of entering a subdomain via an A/AAAA or CNAME record, choose one of these options.
A CNAME record precludes setting any other records for the same subdomain.
The domain or subdomain to which the CNAME record points must have a valid Type A or AAAA record.
If you have a domain ready for the CNAME record to point to, enter DNS records administration by following the instructions in DNS - Domain Records.
Enter the entry according to the following scheme:
Name TTL Type Data
(nazev-subdomeny) 300 CNAME (domain-services)
Common problems
Common problems when setting up subdomains in DNS include:
- Recording * not working properly
- You cannot issue an HTTPS certificate for a subdomain
- The subdomain sub.domena.tld is not working
Recording * not working properly
Problem: After adding a record for a 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 will no longer apply to that subdomain.
Solution: Either add to the subdomain the missing records otherwise set via the * record, or delete the records that cause the conflict.
HTTPS certificate for subdomain
Problem: A DNS-based domain cannot be added to an HTTPS certificate, the following error message appears:
The following domains were found to have a problem when adding to a Lets Encrypt certificate:
www.sub.domena.tld - the domain has no DNS records set.
Cause: by default, the subdomain certificate is checked to add a subdomain variant with www. This can 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 subdomain version with www.
sub.domain.tld not working
Problem: The subdomain named sub.domena.tld is not working.
Cause: You are only entering the subdomain name (sub) without the domain name (domain.tld) in the record name.
Solution: Delete the record named sub.domena.tld and create a new one named sub, copy the rest of the settings from the previous record.
Frequently Asked Questions
Should I set up a subdomain on the webhost?
The server to which the subdomain goes should definitely be configured to handle the subdomain correctly. For our Webhosting, it is sufficient that it is named after the domain or subdomain, and the subdomain files are located in accordance with the Webhosting - Subdomains instructions. The WebSite must be named exactly according to the subdomain (no www).
How do I activate HTTPS on a subdomain?
You set up HTTPS on your web host. Follow the instructions Webhosting - Subdomains.