ASP.NET 3.5: A Beginner's Guide - www.mustafaof.com

20ASP.NET 3.5: A Beginner’s GuideIf you run the same program by referencing the IP address (except for 127.0.0.1),whether it is a LAN address or an Internet IP, you will see a different IP address when yourun the same program on the same computer, as shown in Figure 1-12.As you can see in Figure 1-12, the server address (192.168.0.3) and the addressgenerated by the ASP.NET application are identical. This is because the client and servershare the same IP address.The real test comes when you test your application on a different computer. Then thedifferent computer is the client, and where you have ASP.NET set up is your server.Figure 1-13 shows the program on a computer with Windows XP, while the IIS7 server isset up on a Vista-based operating system on a different computer.In Figure 1-13 you can clearly see that the client’s IP address is different from the IPaddress of the server. By running the ASP.NET application on a remote client, you canbetter see that what you’re getting is not just the local IP address of the server.The acid test to ensure that what you’re seeing is not just a regular web page thatsomehow gets the IP address from your server is to run the ASP.NET application on a clientthat you know positively cannot host ASP.NET. (You probably know that this cannot beaccomplished with HTML or XHTML alone.) Fortunately, one of the clients on the LANis a Macintosh, and if we call the .aspx file up on a Mac, we know that the only way to seethat Mac’s IP address is if we’re dealing with a true server-side application. Figure 1-14shows what you will see in a Safari browser on a Macintosh.Reference to own IP address in browserFigure 1-12 Addressing LAN IP address