Why Is a Message Indicating Conflict with an Existing Record Set Displayed When I Add a Record Set?
If message "This record set is in conflict with an existing one" is displayed, the record set you are trying to add conflicts with or is the same as an existing record set.
Table 1 lists the rules.
| NS | CNAME | A | AAAA | MX | TXT | PTR | SRV | CAA | |
| NS | No limita | Conflict | No limit | No limit | No limit | No limit | No limit | No limit | No limit |
| CNAME | Conflictb | No limit | Conflict | Conflict | Conflict | Conflict | Conflict | Conflict | Conflict |
| A | No limit | Conflict | No limit | No limit | No limit | No limit | No limit | No limit | No limit |
| AAAA | No limit | Conflict | No limit | No limit | No limit | No limit | No limit | No limit | No limit |
| MX | No limit | Conflict | No limit | No limit | No limit | No limit | No limit | No limit | No limit |
| TXT | No limit | Conflict | No limit | No limit | No limit | No limit | No limit | No limit | No limit |
| PTR | No limit | Conflict | No limit | No limit | No limit | No limit | No limit | No limit | No limit |
| SRV | No limit | Conflict | No limit | No limit | No limit | No limit | No limit | No limit | No limit |
| CAA | No limit | Conflict | No limit | No limit | No limit | No limit | No limit | No limit | No limit |
| a: NS record sets cannot be added for second-level domain names. There is no such restriction on subdomains. b: For second-level domain names, CNAME and NS record sets can coexist. For subdomains, CNAME record sets conflict with NS record sets. | |||||||||
The rules are as follows:
- Conflict: The two types of record sets cannot have the same resolution line.
- No limit: The two types of record sets can coexist.
- In the DNS standard RFC protocol, the CNAME record set has the highest priority. If CNAME and other types (such as MX) of record sets coexist, CNAME record set hijacks MX record set in specific scenarios. As a result, the mailbox cannot send or receive emails.
For example, if the local DNS has requested and cached the CNAME record set, when the client requests the MX record set (using the mailbox to send emails), the local DNS preferentially returns the cached CNAME record set instead of requesting the MX record set from the Internet. In this case, the MX record set of the email server cannot be obtained. As a result, the email box fails to send emails.
You are advised to configure different subdomains for an email domain name and a website domain names. For example, if the domain name is used as an email address, do not add CNAME record set for the domain name. Instead, add an A record set to resolve the domain name to an IP address.
- If the address in your CNAME record set is the address of Huawei Cloud WAF or CloudSite, you can add an alias in an A record set to resolve the address to that of WAF or CloudSite.
For details about how to set alias resolution, see Setting Alias Resolution.
- For other solutions, see How Do I Handle the Conflict Between CNAME and MX Record Sets?.
If the message is displayed, perform the following operations:
- Delete the existing record set that conflicts with the record set that you want to add, and then add the record set back.
Deleting a record set may cause domain name resolution to fail.
- Set a different name for the record set.
- Select a different line type.
The following are two examples how you can solve common record set conflicts.
Conflicts when Adding an NS Record Set
You have hosted domain name example.com on the DNS service. An NS record set and an SOA record set are automatically created for the hosted zone and cannot be deleted.
In Table 1, NS record sets cannot be added to example.com in the same resolution line.
In this case, use either of the following methods to add a record set:
- Method 1: Add an NS record set for a subdomain of example.com.
In the following figure, an NS record set is added for 123.example.com, and the value of the record set is ns.example.com.
- Method 2: Add an NS record set to example.com, with a resolution line other than the default line.
In the following figure, an NS record set with the line type set to ISP is added for example.com, and the value of the record set is ns.example.com.
- Method 3: Change the value of the NS record set added to example.com.
To configure a new DNS server address for a domain name, modify the value of the NS record set added to the hosted zone. For more information, see What Are Huawei Cloud DNS Servers?
Conflicts when Adding a CNAME Record Set (Pointing to an Email Server)
If you have hosted domain name example.com on the DNS service, add MX, TXT, or CNAME record sets to example.com.
In Table 1, if the record set names are the same, the CNAME record set conflicts with MX and TXT record sets with the same resolution line. In this case, you can add a CNAME record set with a different name.
For detailed operations, see Table 2.
For detailed operations, see Configuring Email Routing.
| Record Set Type | Name | Value | Description |
|---|---|---|---|
| MX | - | 5 mx01.mailserver.com 10 mx02.mailserver.com | Email server address, which is obtained from the email service provider |
| TXT | - | "v=spf1 include:spf.mailserver.com -all" | SPF records used to prevent spam |
| CNAME | | mailserver.com | Use domain name mail.example.com to log in to the mailbox. |
| CNAME | smtp | smtp.mailserver.com | Use smtp.example.com as the alias of smtp.mailserver.com. |
| CNAME | imap | imap.mailserver.com | Use imap.example.com as the alias of imap.mailserver.com. |
| CNAME | pop | pop.mailserver.com | Use pop.example.com as the alias of pop.mailserver.com. |
Did this article solve your problem?
Thank you for your score！Your feedback would help us improve the website.