alias domains and duplicate content

should I redirect?

[Oliver Henniges]

For several years now I have registered two domain-names, running under the same IP:

www.mykeyword1-mycompanyname.com
www.mykeyword2-mycompanyname.com

The former being my primary domain, the latter being the alias. With the canonical issue coming up last summer, I put some care in redirecting the non-www-version of the former to the www-version, but I did not really care about the alias-domain.

Now, with this new backlink-tool in my webmaster central, I find that google has indexed quite a number of pages of the second alias-domain linking to the primary domain. Should I worry about this? What would be the exact syntax for a proper redirect in my .htaccess? this is my current entry:

RewriteEngine On
RewriteCond %{HTTP_HOST} ^mykeyword1-mycompanyname\.com [nc]
RewriteRule (.*) [mykeyword1-mycompanyname.com...] [R=301,L]