Connect To Unprotected HotSpot Using Only Command Line

nythacker · 03-04-2009, 01:29 PM

Hi,

Can anybody show me how to search and connect to an unprotected/open wifi hotspot (e.g. Internet Cafe, hotels, airports, etc.) using only the command line?

I'm using Ubuntu 8.04 (a.k.a "Hardy Heron")

Any help would be greatly appreciated. Thanks!

acid_kewpie · 03-05-2009, 06:39 AM

just use the iwconfig tool to set your AP, and iwlist to find available hotspots. Once you're associated you'd normally then run a dhcp client against the interface to get an ip.

pixellany · 03-05-2009, 06:44 AM

These commands can be tricky. I have found that I often have to run iwconfig, then do "ifconfig wlan0 down", then bring it up again, then maybe run iwconfig again. I have no idea what is going on in the background, but GUI front ends such as WICD seem to work pretty seamlessly.

nythacker · 03-05-2009, 08:01 AM

I did some research and found that you first need to use the command

Code:

sudo iwlist [interface] scan

to be able to find available wireless networks within your area.

Then you use a series of iwconfig commands to configure your wireless interface to point to one of the wireless networks found by the iwlist [interface] scan command.

Then you finally issue the command

Code:

sudo dhclient [interface]

to get an IP Address from the selected wireless network.

My question now is what essential iwconfig commands are needed to configure my wireless interface to connect to the open/unprotected wireless network or hotspot.

Thanks.

pixellany · 03-05-2009, 08:13 AM

Quote:

Originally Posted by nythacker

My question now is what essential iwconfig commands are needed to configure my wireless interface to connect to the open/unprotected wireless network or hotspot.

Thanks.

Good to see the quick learning.....

In your problem statement, "essential" means that you have to know "enough" to connect to the hotspot. If it is not protected, then normally all you need is the essid. If this is not hidden, then you will get it from "iwlist ... scan".

Best case example:
iwlist wlan0 scan ##finds one open hotspot with essid = "fred" (and adequate signal strength)
iwconfig wlan0 essid fred
dhclient (or dhcpcd wlan0)

nythacker · 03-13-2009, 12:17 PM

Quote:

Originally Posted by pixellany

Good to see the quick learning.....

In your problem statement, "essential" means that you have to know "enough" to connect to the hotspot. If it is not protected, then normally all you need is the essid. If this is not hidden, then you will get it from "iwlist ... scan".

Best case example:
iwlist wlan0 scan ##finds one open hotspot with essid = "fred" (and adequate signal strength)
iwconfig wlan0 essid fred
dhclient (or dhcpcd wlan0)

Thank you so much, Pixellany. Your solution worked on mine...