How to protect against duplicate content?

[williammarlow]

I just discovered that my company's 'dev website' (which mirrors our actual website, but which is where we add content before we put new content to our actual website) is being indexed by Google.  My first thought is that I should add a rel=canonical tag to the actual website, so that Google knows that this duplicate content from the dev site is to be ignored.  Is that the right move?  Are there other things I should do? Thanks!

[Francisco_Meza]

No index No Follow in the header.

[KeriMorgret]

Is it on its own domain or subdomain? You can exclude the entire thing in robots.txt, then verify the site in GWT and request exclusion of the entire dev site.