I have a server called cname.booking.com.au.
I'd like to be able to create multiple other websites, that are like a customised version of cname.booking.com.au. For example I'd like to create a website called booking.updog.com.au.
So in my DNS settings for booking.updog.com.au I created an entry: booking 3600 IN CNAME cname.booking.com.au.
I expected that when I browse booking.updog.com.au, it would produce the same content as cname.booking.com.au, with the ability to customise the look and feel so that it looks like a different website, but it doesn't work. I don't know why.
The only way I can see this working is if cname.booking.com.au can somehow have a Virtual Host setting somewhere that maps booking.updog.com.au to an IP address, but I don't know how.
Someone who has done this successfully is Campaign Monitor. Campaign Monitor has a server called cname.sendcreate.com and I have a website called email.marketingmix.com.au and in my DNS settings I have a record: email 3600 IN cname.sendcreate.com and it works. So I think if I understood how something like cname.sendcreate.com is setup, I'd be able to answer my own question.