A recent question I have been seeing a bit is where people ask:

I have duplicant content issues on my website, do I add the canonical tag and also the no index tag?

My answer is the following:

No only add the Canonical tag you do not need to add the no index tags once a canonical tag has been implemented.

Google has also weighed into this question and provided similar advice here:

Rel Canonical and No index

Rel Canonical and No index