SharePoint helps us create multiple zones for a single website e.g. Intranet (accessed only within an organization), Extranet (accessed within an organization + few limited users over web), Internet (mainly for public users), etc. Every SharePoint website has its default start page set as default.aspx. Even if we have separate zones for a website but still the data gets managed from a single content database and because of which we see the same default start page while accessing any zone.
But sometimes depending on the requirements we need to set different default start page for different zones. The first things which comes to our mind is to change the default document association within the IIS Manager for the website belonging to that zone. But the bad part is, it does not fulfill the needs and you still see the same start page for all the zones.
So, can this be achieved and will we be able to meet the above requirement for setting different start page for each zone? Yes, we can! We can achieve this by customizing the web.config file for the specific zone.
E.g.
Lets say I want to set the start page for Internet zone from ‘default.aspx’ to ‘home.aspx’. For this I need to open the web.config file from within the Virtual Directory belonging to that zone. Add the “UrlMapping” attribute provided below under the System.Web section of the config file (this helps set the custom start page for the specific zone).