Magento redirects to base url using 302, how do I get it to use 301

Question

I've notice in firebug that the non-www version of my magento store redirects to the www version using 302. For SEO purposes I want it to redirect using 301.

How I tried to fix it

I went to the System > Configuration > General > Web > Url Options and my setting Redirect to Base URL if requested URL doesn't match it is set to Yes (there are only 2 options: Yes or No)

Imporantant notes

I'm using Magento v1.4.0.1 My .htaccess file contains the following, in regards to URL Rewrites:

<IfModule mod_rewrite.c>
    Options +FollowSymLinks
    RewriteEngine on
    RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
    RewriteCond %{REQUEST_URI} !^/(media|skin|js)/
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteCond %{REQUEST_FILENAME} !-l
    RewriteRule .* index.php [L]
</IfModule>

How can I change the redirect method to 301?

Answer 1

Try changing the last line to this:

RewriteRule .* index.php [R=301,L]

See Apache mod_rewrite RewriteRule Directive the section about flags.

Answer 2

As of 1.6.2.0 there seems to be an option to select the redirect method in the Admin Panel, no need to modify the .htaccess.

Simply go to System -> Configuration -> Web -> Url Options and set Auto-redirect to Base URL to your preferred method.