Hi Max,

As you know, SEOmoz uses a CDN (Content Delivery Network) to host our static content. This greatly improves the load time of our pages by distributing our content across a cloud network, and results in an improved experience for users.

If I understand your question correctly, you have set up a CDN and have created duplicate content issues.

To solve this, it's important to set up your CDN only to serve static content, like images, stylesheets and javascript. That is what a CDN is designed for. Do not duplicate your entire site - your HTML - as this will cause duplicate content issues.

If for some reason you need to replicate your entire HTML, then there are some steps you can take to mitigate the damage, although it's going to depend on your exact circumstances.

For example, you can set full URL canonical tags so that all your mapped CNAMES point to your primary URL.

To revert back to one copy of your HTML, you might want to put 301 redirects in place on the duplicated content (pointing to the original) before removing them from the CDN.

But even these aren't ideal solutions. It's best just to serve your static content, and only one version of your HTML.