Preventing CNAME Site Duplications

[David-Kley]

Hello fellow mozzers!

Let me see if I can explain this properly.

First, our server admin is out of contact at the moment,
so we are having to take this project on somewhat blind. (forgive the ignorance of terms).

We have a client that needs a cname record setup, as they need a sales.DOMAIN.com to go to a different
provider of data. They have a "store" platform that is hosted elsewhere and they require a cname to be 
sent to a custom subdomain they set up on their end.

My question is, how do we prevent the cname from being indexed along with the main domain? If we 
process a redirect for the subdomain, then the site will not be able to go out and grab the other providers
info and display it. Currently, if you type in the sales.DOMAIN.com it shows the main site's homepage.
That cannot be allow to take place as we all know, having more than one domain with
exact same content = very bad for seo. I'd rather not rely on Google to figure it out.

Should we just have the cname host (where its pointing at) add a robots rule and have it set to not index
the cname? The store does not need to be indexed, as the items are changed almost daily.

Lastly, is an A record required for this type of situation in any way?

Forgive my ignorance of subdomains, cname records and related terms. Our server admin being
unavailable is not helping this project move along any. Any advice on the best way to handle
this would be very helpful!

[Yeeply.com]

Hello David,

I think with the robots rule (there are many examples out there) should be more than enough in your case! take a look at this helpful article: http://moz.com/community/q/block-an-entire-subdomain-with-robots-txt

I hope that was helpful! Sorry about my English... I'm Spanish

Luis

[AlanMosley]

You need to point your cname to the ip of the server that hosts your sales.domain.com

don't

sales.domain.com > domain.com

Do

sales.domain.com > 123.123.123.123

where 123.123.123.123 is the ip of the hosting webserver.

[David-Kley]

So does this work better because Google will not show an IP address in search results?

[AlanMosley]

No,
it is because you are pointing sales to a different sever, it seems to me that you don't have your dns set up correctly. you don't want sales pointing to your main website.

[David-Kley]

It is pointing to the other server now. We have it blocked from indexing on that end, just wanted to make sure that was enough.