3 domains(.com, .ca, .net) and how to avoid duplicate content

[machine11]

Hey guys, I`m running an ecommerce site with 3 domains --- .com, .ca and .net all liked to the same content.
What`s the simplest way to avoid duplicate content?
I saw that in google, the .com and the .net pages are already being idexed. I`m afraid of duplicate content even though I only have one database. (godaddy) I`m not really sure what to do.
thanks!

[encyclo]

Welcome to WebmasterWorld machine11. :) The standard answer is that you need a 301 permanent redirect to your preferred domain name (ie. choose one out of the three and redirect to that).

Do you know if your server is running Apache, and if so whether you can use mod_rewrite? If so, then you'll see a number of threads on the subject in the WebmasterWorld Apache forum [webmasterworld.com] (check out the library).

[machine11]

thanks encyclo :) I appreciate the help!
I realised I was doing domain aliasing... So i stopped this right away and will do the redirect option instead! :)
thanks again,
Alain