Addon Domain - how to avoid duplicated content

[Oxydada]

I've been reading about the subject, and found that there are two ways to avoid duplicated content when setting up an addon domain.
One is setting the addon folder inside the main domain as "noindex" in robots.txt
The other one is using redirects.

I was wondering, wich one is better, safe?

I'm planning to add another domain to my shared account trough addon domains in CPanel. The new site will be completely unrelated to the main one.

My main domain is well established, so I'm very afraid to mess thing up as I'm a complete newbie about this "addon thing".

Any tips will be highly appreciated!

Please bear my English :)

[sonjay]

A 301 redirect is the way to go - redirect from example.com/addon to the addon domain. No-indexing it would keep the search engine spiders out, but it wouldn't redirect them to the addon domain, and it also wouldn't redirect any humans who ended up there -- meaning that the content would be available at two different URLs. Better to set up a canonical redirect so that each page in the addon domain is only available through one single URL.

[Oxydada]

Thank you sonjay! I will do redirects then :)