NYCPHP Meetup

[csnyder]

I can't see how A vs. CNAME records can possibly make a difference to
crawlers. CNAME is simply a matter of convenience within DNS -- it
allows you to change the IP address on one A record and have it apply
to many hostnames.

It has nothing to do with HTTP or Redirects at all. 

That said, all of John's comments apply at a higher level, which is
where you should be concerned if multiple virtual hosts point to the
same content.