What is the magic behind that DOT which makes Fiddler work?

Question

It took me a while to learn that I have to put a dot after the "localhost" in the URL so that I can use fiddler with my development server.

Why do I need to put this dot here to make fiddler work for my local:

http://localhost.:1888/MyPage.aspx

What does it stand for?

thanks

Answer 1

It's not that you're making fiddler work, but you're making Internet Explorer work. Internet Explorer is written specifically to bypass the proxy server for "localhost" . By attaching a trailing dot, you're providing a valid DNS name that does not match the mechanism within IE that checks the domain (IE does a stricmp(userdata, "localhost") or equivalant).