I have been told I can have two A records on my domain, one with www and one without. However, I have been told can cause SEO issues because google will take it as duplicate content. However when I asked someone about it they said the following:
Google has understood this common configuration for years now. That's ancient SEO advice. If you're really concerned about it, you can always put a canonical meta tag in place to be explicit about it
My question is, assuming I cannot use a redirect (for the sake of this question), is there any SEO impact by having both the naked and the www url on the same CNAME record? Please provide some sort of written example, because there are so many conflicting views.