CDN: how to prevent Google accessing duplicate content?

[seoid]

Little help needed!

Recently I moved static content of my image sharing site to CDN and I am afraid of penalisation for duplicate content, because Google indexed sooner all content on mydomain.com and now it is duplicated on CDN on static.mydomain.com.

Can it be a reason for penalisation for duplicate content? There are just images and HD videos, I don't know if rules on duplicate content apply on this type of content.

Anyway, I need solution to prevent Google from accessing content on my domain a redirect it to CDN subdomain.

HTACCESS I guess?

[tstolber]

You should use either one of the two following solutions

1) Robots.txt
If you want both sites to be live, accessible and independent you should use robots.txt to prevent indexing of the newer version of the content. The original indexed content should be visible to search engines and not blocked in robots.txt

2) 301 Redirect (in .htaccess)
If you are just moving the site to a new location and don't need the existing original site to be live then 301 redirect it to the new location.

[seoid]

You should use either one of the two following solutions

1) Robots.txt
If you want both sites to be live, accessible and independent you should use robots.txt to prevent indexing of the newer version of the content. The original indexed content should be visible to search engines and not blocked in robots.txt

2) 301 Redirect (in .htaccess)
If you are just moving the site to a new location and don't need the existing original site to be live then 301 redirect it to the new location.

Thank you! I managed to find following advices:

First create .htaccess rewrite:

RewriteEngine On
RewriteCond %{HTTP:VIA} ^.*\.worldcdn\..*$
RewriteRule ^robots\.txt$ robots_cdn.txt [L]

And then create robots_cdn.txt:

User-agent: *
Disallow: /