Internet comes in via wifi, was using a windows server to then share that out via ethernet. Just installed latest Ubuntu Server 8.x.

I was able to connect on sunday via linux server, and still am today via windows desktop machine, but not via linux server any longer. The problem seems to be that I can't get the wlan0 interface out of Open mode.

I've tried:

iwconfig wlan0 key restricted xxxxxxxxxx
iwconfig wlan0 enc restricted xxxxxxxxxx

iwconfig wlan0 key xxxxxxxxxx restricted
iwconfig wlan0 enc xxxxxxxxxx restricted

and many others, yet every time I "iwconfig wlan0" it shows its network key, and it shows it as being "Open". I swear I remember it working before I ran dhclient on sunday when it worked (that was the day I did the install).

Now dhclient just fails every time.

I am setting essid, and channel properly. It's just this one thing I can't figure out. The man pages seem to indicate that once I set a key it should automagically go into restricted mode.

Little help?

Welcome to LQ!

If I remember correctly, Ubuntu uses ifup, not dhclient. You might give that a try and see if it behaves better than dhclient. Also, have a look in your logs and see if dhclient/ifup are leaving any errors that might give us a clue as to what is going wrong.