Will browsers request /favicon.ico or <link> first?

Question

I want to set a favicon to be requested from a static file server instead of the main web server for performance optimization.

If I specify a <link rel="shortcut icon" href="http://cdn.site.com/favicon.ico"> but also have a /favicon.ico in my site root as a fallback, which will browsers prefer? Will browsers (and which?) still look for /favicon.ico, making the move to a static file server useless?

Answer 1

I did the test suggested above. I placed a /favicon.ico in the root of a domain, and a link, and fired up the page in:

1. Opera 10
2. Opera 9.64
3. Firefox 3.5
4. IE 6
5. IE 7
6. IE 8
7. Safari 4

They all showed the icon loaded with <link rel="shortcut icon" href="http://cdn.site.com/favicon.ico"> (located on an external server). I checked access.log, and there were no requests to /favicon.ico!

I then commented out the <link>, checked again in all browsers, and they showed the /favicon.ico icon and corresponding entries in access.log.