Redirecting in Umbraco is usually a very simple affair, except when you're trying to redirect from the root node of your site.
Method 1:
It explains it best here : https://our.umbraco.com/Documentation/Reference/Routing/Routing-Properties/
So it's possible by adding a umbracoInternalRedirectId property to your root node, with the data type of Content Picker. Note that it does not redirect the user but instead load the contents of that page inside the current url. So the URL will remain as http://www.example.com whilst serving the contents of the page that you want to redirect to.
Method 2:
If you really want it to change from http://www.example.com/ to http://www.example.com/index.aspx. I usually add something like the following code to the template of the root node.
<%@ Master Language="C#" MasterPageFile="~/umbraco/masterpages/default.master" AutoEventWireup="true" %>
<asp:Content ContentPlaceHolderID="ContentPlaceHolderDefault" runat="server">
</asp:Content>
<script type="c#" runat="server">
protected void Page_Load(object sender, EventArgs e)
{
Response.Redirect("http://www.example.com/index.aspx");
}
</script>
So that ASP.Net is responsible for the redirect. But it obviously won't handle node rename/moving too well.
