In my GoDaddy DNS manager, I made some A Record that points to *.mirror for my domain

enter image description here

Now when I access URL 123.mirror.mydomain.com from the browser I can see that my app is loaded, and its all OK.

My problem now is when doing a CNAME point to the URL above on another domain like this:

enter image description here

Accessing 123.otherdomain.com which I expect to "forward to" 123.mirror.mydomain.com I only get this 404 error:

enter image description here

The IP is actually ghs.googlehosted.com

What I am missing here? Why 123.otherdomain.com which points to 123.mirror.mydomain.com cannot open that page and I think google is handing the web page request?

1 Answer 1


This is rather simple. You cannot just redirect traffic anyway you want with DNS. That is not what it does. In this case, it appears that you only have one half of the equation.

What you are missing is that the HTTP request packet header has a domain address within it that the web server compares to it's list on known sites. You are packaging request packets with 123.mirror.mydomain.com in the header and your web server does not have a matching site for this address. You would have to create the 123.mirror.mydomain.com site on your web server and potentially redirect it to where you want it to go if that is what you want to do- otherwise, that is where you would deploy the site you intend.

  • Yes, I have my GAE app to handle *.mirror.mydomain.com like this: 123.mirror.mydomain.com
    – xybrek
    Aug 24, 2014 at 12:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.