Support for SRV with Port "0" and Target "."


I’m asking for Cloudflare support on SRV record with entry of 0 0 0 .

Currently, Cloudflare requires port number to be greater then or equal to 1 and setting the target to . automatically changes it to the current domain used.

But per RFC 2052,

The port on this target host of this service. The range is 0-65535. This is often as specified in Assigned Numbers but need not be.

As for MX, the domain name of the target host. There MUST be one or more A records for this name. Implementors are urged, but not required, to return the A record(s) in the Additional Data section. Name compression is to be used for this field.

A Target of “.” means that the service is decidedly not available at this domain.

So, the RFC said that the range of 0 and the target of . is a valid entry. Could Cloudflare support these entry?

For a use-case, please refer to RFC 6186 regarding “Use of SRV Records for Locating Email Submission/Access Services” at Section 3.4