I am planning to serve images on a CDN using a CNAME: images.mysite.com. I am doing this because CDNname.mysite.com makes ugly URL's and MAY be bad for SEO (debatable).
Will Google crawl the subdomain (only storing images and nothing on the main domain will link to it).
If so, would a simple robots.txt be suitable? Is this even possible seeing that the subdomain is ONLY serving images, JS, CSS i.e. not HTML?