CNAME url on site transfered to

Question

Is it possible to have the site you transfer to from a CNAME and 'A' record keep the name from the CNAME in the url? Example: Site 123.com has a CNAME called app pointing to abc.com. When I type in app.123.com, it transfers me to abc.com and keeps app.123.com in the url on the first page that I transfer to. But once I click anything on the page to move around within the page, the url reverts back to abc.com. Is it possible to have the app.123.com stay in the url while I move around. So instead of changing to abc.com/otherPage.php, it would stay app.123.com/otherPage.php?

Thanks for any help!

Answer 1

There are two different mechanisms at work here, DNS and HTTP.

When you use a URL containing app.123.com, that's looked up using DNS and gives the IP address that happens to be the same as the IP address configured for abc.com

But once you're viewing that page, the HTML of that page will determine how the links work, they may be absolute URLs including abc.com or they may be relative URLs, so behaviour could vary.

A site can be made to work under multiple aliases but it would need to use the request headers to detect the address used by the client and alter content accordingly.