IIS7 URL Rewrite - Add "www" prefix

Question

How to force example.com to be redirected to www.example.com with URL rewriting in IIS7? What kind of rule should go into the web.config? Thanks.

Answer 1

Not sure about the best possible way to do this, but I have a site with all old domains / subdomains running this web.config:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <rewrite>
            <rules>
                <rule name="Transfer" stopProcessing="true">
                    <match url=".*" />
                    <action type="Redirect" url="http://www.targetsite.com/{R:0}" redirectType="Permanent" />
                </rule>
            </rules>
        </rewrite>
    </system.webServer>
</configuration>

Seems to get the job done.

Answer 2

This is Microsoft's sample for URL Rewrite Module 2.0 that redirects *.fabrikam.com to www.fabrikam.com

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <rewrite>
            <rules>
                <rule name="Add www" patternSyntax="Wildcard" stopProcessing="true">
                    <match url="*" />
                    <conditions>
                        <add input="{HTTP_HOST}" pattern="www.fabrikam.com" negate="true" />
                    </conditions>
                    <action type="Redirect" url="http://www.fabrikam.com/{R:1}" />
                </rule>
            </rules>
        </rewrite>
    </system.webServer>
</configuration>