As part of my work for a project I stumbled upon a very common problem for SharePoint developers – configuring URLs using Alternate Access Mappings (AAM). This is considered one of the least understood parts of the development process and therefore most of the information on this matter I found on the web is confusing and not very detailed. In this blog post I will try to summarize the information I got from couple of different sources including articles and videos in order to provide a more clear understanding on what AAM is and what is the right way to configure it.
What Is Alternate Access Mapping (AAM)?
Alternate access mappings enable a Web application that receives a request for an internal URL, in one of the five authentication zones, to return pages that contain links to the public URL for the zone. You can associate a Web application with a collection of mappings between internal and public URLs. The difference between the two is described later on in the post.
Steps To Configure AAM
1) Access SharePoint Central Administration from the icon in the Start Menu:
2) Click on Application Management, then – Configure alternate access mappings
3) Select the targeted AAM collection (web application):
4) Now you have the options to either Edit Public URLs or Add Internal URLs. The difference is the following:– Internal URL defines the URL(s) that SharePoint deems as viable requests coming into SharePoint. The Internal URL is represented by the “HTTP GET” request coming from the client. If the internal URL has been modified by a reverse proxy device, it can differ from the public URL.– The Public URL is essentially the root to all relative URLs. It defines with which URL root each anchor tag will be stamped when the page is built by the server and returned to the requesting client. When editing the Public URLs you have the options to edit 5 different zones – Default, Intranet, Internet, Custom and Extranet.
5) Another option is to define mappings for resources outside intranet applications. This can be done by clicking on the Map to External Resource link on the Alternate Access Mappings page.