How to update iphone 3gs to ios 5.1.1? - 1

My iphone 3gs is on ios 4.1, I wanted to update to ios 5.1.1 but everytime I want to update with preserved baseband with redsn0w, and tried shift + restore to update but error 3194 pops up and I tried adding:
74.208.105.171 gs.apple.com
74.208.10.249 gs.apple.com
to hosts file but nothing changed, I appreciate your answers…

Thanks

Added (1). But i don't wanna update to ios 6.0.1

Added (2). @Tyler, oh really? U sure?

Net-cellphones.cu.cc

>plug into computer
> go to iTunes

> click on your device
>click update