This article covers the DNS record types ALIAS, CNAME and DNAMEin detail. For general instructions on DNS records and how to set them up in the Customer Administration, see the article DNS – Domain Records.
In this article you will read:
- How an ALIAS record works
- How a CNAME record works
- How a DNAME record works
- Common problems
- Frequently Asked Questions
ALIAS record
An ALIAS record (sometimes called ANAME) is used to point the main domain to an existing domain or subdomain. Some hosting providers prefer this record type over A and AAAA records.
If you need to point your own subdomain to a provider’s domain or subdomain, use a CNAME record.
An ALIAS record works only on primary DNS servers. When the record is created, the system automatically looks up the currently set A/AAAA records for the ALIAS value (if any exist) and inserts them into DNS. Updates are handled by automatic synchronization, so how up to date the records are depends on the TTL of the ALIAS, the TTL of the relevant records on the source domain (or on other domains in the chain), and other circumstances.
In the domain zone, ALIAS therefore does not appear as an ALIAS record, but as the current A/AAAA records of the target name. You can see them, for example, in the left menu Current status. Synchronization usually takes place approximately every 5 minutes. A change of IP addresses at the target will therefore usually show up in your domain’s zone within 5 minutes, plus the TTL of the records.
We do not guarantee the synchronization time of A/AAAA records with the ALIAS.
Entering ALIAS records
For general instructions on setting up DNS records in the Customer Administration, see the article DNS – Domain Records.
If the domain uses other DNS servers changes to VEDOS records will not affect its behavior.
An ALIAS record must be on the main domain. The field Name must therefore be empty.
When entering the record, follow these rules:
- ALIAS can only be entered for the main domain. Subdomains (e.g. www or mail) do not support ALIAS; for them, use a CNAME record.
- When entering via WAPI, the name @ is converted to an empty name.
- An A or AAAA record, or a second ALIAS record, must not exist on the main domain at the same time.
In the field Data enter the name of the domain or subdomain that the main domain should point to. Omit the protocol (http, https) from the name. Also do not enter IP addresses in the field Data , as those are entered using A and AAAA records.
Name TTL Type Data
(leave empty) 300 ALIAS (domain or subdomain name)
Example of an ALIAS record
Example: (Not actually functional) ALIAS record for default.wedos.net.
CNAME record
CNAME records are used to point a subdomain to an existing domain or subdomain. The most common uses include pointing subdomains to a Webhosting that requires or supports this type of routing, or to services such as FTP, SMTP, POP/IMAP.
Because a CNAME effectively turns one subdomain into another (sub)domain, you cannot create records of any other type for a subdomain that has a CNAME record, and vice versa.
A CNAME record must also lead to a (sub)domain with an A or AAAA record. You cannot chain several CNAME records one after another.
Finding service addresses
If you want to use a CNAME record to simplify access to various VEDOS services, use this guide:
- FTP: You can find the FTP server address of your Webhosting in the guide FTP – Login.
- SMTP, POP/IMAP: You can find the mail server addresses in the guide Email – SMTP, POP3, IMAP.
You can find a usage template in the chapter Examples of CNAME records.
If the service whose address you want to find is not hosted at VEDOS, look up the help for that service or contact its provider’s support.
Entering CNAME records
For general instructions on setting up DNS records in the Customer Administration, see the article DNS – Domain Records.
If the domain uses other DNS servers changes to VEDOS records will not affect its behavior.
A CNAME record must be on a subdomain. The field Name must therefore contain the * character or the name of a specific subdomain; it cannot be empty.
In the field Data enter the name of the domain or subdomain that the subdomain should point to. Omit the protocol (http, https) from the name. Also do not enter IP addresses in the field Data , as those are entered using A and AAAA records.
Name TTL Type Data (* character or subdomain) 300 CNAME (domain or subdomain name)
Examples of CNAME records
Example: Webhosting FTP server as the subdomain ftp.domain.tld:
Example: POP, IMAP and SMTP servers as the subdomains pop, imap and smtp:
Example: Pointing the subdomain www and all of its subdomains (*.www) to the external service www.wds-test.cz.
DNAME record
WEDOS supports DNAME records only on subdomains.
DNAME records work similarly to CNAME, but instead of a single specific subdomain, they redirect all lower-level domains under the given subdomain (except the subdomain itself). With this redirection, they preserve the structure of these lower-level subdomains relative to the target subdomain.
Other differences compared to CNAME are:
- It does not apply to the specified subdomain itself, only to all of its subdomains, whereas CNAME works only for the specified subdomain and nothing else.
- They allow you to enter other records for the given subdomain as well, whereas CNAME is incompatible with any other record (including DNAME) for the given subdomain.
Common problems
Common problems with ALIAS, CNAME and DNAME records include:
An ALIAS record cannot be created
Problem: An error is displayed when you try to create the record.
Cause: The ALIAS record conflicts with another existing record, or you are entering it as a subdomain.
Solution: Make sure that:
- You are entering the record without a name.
- There is no A, AAAA or ALIAS record without a name in the DNS records. If you find such a record, delete it.
A subdomain record cannot be created
Problem: An error is displayed saying that the new record cannot be created because a CNAME record already exists for the subdomain.
Cause: If a CNAME record exists for a subdomain, you cannot create a record of another type for it, and conversely, you cannot create a CNAME for a subdomain with an existing record of another type.
Solution: Delete the conflicting records.
Frequently Asked Questions
Can I enter an ALIAS record for a subdomain?
Currently you cannot. Use a CNAME record instead.
The provider of the target service has changed the IP address. How long will it take ALIAS to pick it up?
Usually within approximately 5 minutes, plus the TTL of the records. However, we do not guarantee the synchronization time.
I entered an ALIAS record, but I can’t see it in the current DNS status. Is that an error?
No. In the domain zone, ALIAS is displayed as A/AAAA records with the current IP addresses of the target. If the target has no A/AAAA records, nothing is inserted.
Can I enter an IP address in the Data field of an ALIAS record?
No. Enter the name of the target domain or subdomain. Enter the IP address of the main domain using a record of type A or AAAA instead of ALIAS; you cannot have both at the same time.
My old hosting had a CNAME record with the name www and the data www.provider.tld. How do I change this record so that it points to hosting at VEDOS?
VEDOS does not use this type of routing. Delete the record and replace it with an A record with the name * and data matching the IP address of your Webhosting.
What if I have a CNAME record with the name * and I want to add the subdomain shop with a different CNAME or another record type?
A record with the name * applies only to those subdomains that have no other DNS record. You can therefore add the subdomain shop with any record type, including CNAME, without any problem.