You install the Web Server (IIS) server role on two servers named Server1 and Server2.
The servers run Windows Server 2008 R2.
Your company has a Web site named www.contoso.com hosted on Server1.
The Web site is due for maintenance. The Web content must be available during maintenance.
You create a mirror Web site located on Server2.
You need to configure the www.contoso.com site to redirect requests to Server2.
What should you do first?

A.
Run the appcmd set config /section:httpRedirect /enabled:true command.

B.
Run the appcmd set config /section:httpRedirect /enabled:false command.

C.
Run the appcmd set site /site.name:contoso /-bindings.[protocol=’http’,www.contoso.com] command.

D.
Run the appcmd set site /site.name:contoso /+bindings.[protocol=’http’,www1.contoso.com] command.

Explanation:
To enable redirection
You can perform this procedure by running Appcmd.exe commands in a command-line window.
Command Line
To enable or disable redirection, use the following syntax:
appcmd set config /section:httpRedirect /enabled:true|false /destination:location
By default, the redirection feature is disabled, but you can enable it by specifying true for the enabled attribute and configuring the location to which to redirect users in the destination attribute. For example, if you want to enable redirection and redirect users to http://www.contoso.com, type the following at the command prompt, and then press ENTER:
appcmd set config /section:httpRedirect /enabled:true /destination:http://www.contoso.com
Source: http://technet.microsoft.com/en-us/library/cc732930(WS.10).aspx