wireless network

iPhone/iOS: How to quit using cellular data when using WiFi

I live in Colorado, where cellular reception can be very hit or miss. As just one example there are only two spots in my apartment where I can make a phone call. So when I’m at home trying to view a website using Safari on my iPhone and the page is loading really slow, I find it really annoying that my iPhone is trying to use my cellular data rather than my home wireless network (WiFi).

Note: Apple implies that the cellular data is “assisting” the WiFi, but with the poor cell reception here, I can confirm that this feature just slows down my iPhone internet speed.

How to restart Mac OS X networking from the command line

I've been having a problem with my MacBook Air (running Mac OS X Lion) and my wireless router, so today I decided to write a script to restart the OS X wireless networking service from the command line. In short, I use this OS X command to turn off the Mac networking service:

sudo ifconfig en0 down

and I use this command to turn the Mac wireless network service back on:

sudo ifconfig en0 up

(I found these commands on the website I linked to.)