SRV record with cname

Question

I bought a hosted service which, mainly for DDoS mitigation reasons, often rotates its IPs. So myservice.remoteserver.xxx:666 sometimes goes either to 111.111.111.111:666 or 222.222.222.222:666

I actually got a CNAME record on my own server: sub.mydomain.yyy -> myservice.remoteserver.xxx. This is so that anybody is able to access the service at sub.mydomain.yyy:666.

I would like users to be able to reach the service (SRV compliant) omitting to specify the port (666). How may I accomplish this?

I wrote a SRV entry sub1.mydomain.yyy -> 1 1 666 myservice.remoteserver.xxx, but it doesn't work!

Wikipedia says:

As in MX records, the target in SRV records must point to hostname with an address record (A or AAAA record). Pointing to a hostname with a CNAME record is not a valid configuration.

So, should I get an A record in my own DNS? sub.mydomain.yyy -> 111.111.111.111

Or it would be enough to point to my service provider A record (for example: idontknow.otherremoteserver.xxx -> 111.111.111.111)?

• To clarify this last question: Since I am sure the address they gave me myservice.remoteserver.xxx is a CNAME for something else, I may dig and find out the final A record idontknow.otherremoteserver.xxx -> 111.111.111.111

Answer 1

The only way to omit the port number from the URL of your website is to run the service on port 80 (the default port).

SRV records cannot be used with websites. SRV records are not supported by browsers. The reason for this is provided by Teddy in Why do browsers not use SRV records?

The RFC for SRV records specifies that it may not be used by pre-existing protocols which did not already specify the use of SRV records in their specifications. I.e. no SRV in the HTTP spec - browsers are, by the SRV standard, prohibited from using it.

This does not prohibit a new HTTP 1.2 standard from specifying the use of SRV records, though. However, Mark Andrews proposed this in April 2007 to the IETF HTTP working group, but got no response.