Reverse Tethering help

[Guest fwoop]

i did this guide to reverse tether my phone via usb

http://blog.mycila.com/2010/06/reverse-usb...android-22.html

but then im stuck at step 4

if i input adb shell netcfg usb0 dhcp on my pc i get the error "action 'dhcp' failed <No such device>"

and if i input netcfg usb0 dhcp on my phone i get "action 'dhcp' failed (permission denied)"

any ideas?