How does Google see different file extensions?

Asp. vs. Aspx

[talismon]

We are currently re-designing our site and changing the url's from asp to aspx. Will google identify these pages as the same or do I need to 301 the asp to aspx? The rest of the url structure will be exactly the same.

Thanks!

[the_nerd]

They are completely different files in google's eyes.
You could either use 301s as you mentionend or - use .aspx as real filenames, but rewrite the names. This way they'd look like .asp to everyone including google.