Remove "www" from domain by forwarding 301

Question

How do I redirect a www.dominio.com.br for dominio.com.br (www-free)?

I’m using Asp.net mvc.

Answer 1

Note: At first I thought it was a duplicate of How to redirect from non-www to www? but while reading I noticed that the question here is to remove "www" and not add, in the other question I did not see examples of removing "www" so I am answering here.

I found two answers in Soen:

• Editing the web config. (the redirectType="Permanent" indicates permanent redirect which is 301):

  <system.webServer>
      <rewrite>
          <rules>
              <rule name="Remove WWW prefix" >
                  <match url="(.*)" ignoreCase="true" />
                  <conditions>
                      <add input="{HTTP_HOST}" pattern="^www\.domain\.com" />
                  </conditions>
                  <action type="Redirect" url="http://domain.com/{R:1}" redirectType="Permanent" />
              </rule>
          </rules>
      </rewrite>
  </system.webServer>
  

  If you prefer to add www, switch to:

              <add input="{HTTP_HOST}" pattern="^domain\.com" /> 
          </conditions> 
          <action type="Redirect" url="http://www.domain.com/{R:1}" redirectType="Permanent" /> 
      </rule> 
  

• Using the programming language, in this case an example with C#:

  protected void Application_BeginRequest(object sender, EventArgs e)
  {
     if (Request.Url.Host.StartsWith ("www") && !Request.Url.IsLoopback)
     {
        UriBuilder builder = new UriBuilder(Request.Url);
        builder.Host = Request.Url.Host.Replace("www.","");
        Response.StatusCode = 301;
        Response.AddHeader("Location", builder.ToString());
        Response.End();
     }
  }
  

  If you prefer to add www, switch to:

  UriBuilder builder = new UriBuilder(Request.Url);
  builder.Host = "www." + Request.Url.Host;