Open vs Shared
WEP can work in two different modes, open and shared. Some devices play better with one WEP variant or the other. You can switch like so:
iwpriv ath0 authmode 1 // open iwpriv ath0 authmode 2 // shared
Somewhat counterintuitively, both variants support encryption and can be used in conjunction with iwconfig ath0 key HEX_KEY_HERE restricted. The primary difference between open and shared is that the latter has a challenge-response handshake during association. In a bizzare twist, the extra protocol makes shared less secure than open. (This is likely a side effect of the fact that WEP has been cracked for years.)
How do I get my card to use WEP? I get ath0: authorization failed (reason 13)
If you have trouble with iwconfig when using WEP, specifically if you can’t set the essid or associate with an access point, then it may be the order in which you are issuing the iwconfig commands. Silas Bennett recommends the following order:
iwconfig ath0 key XXXXXXXXXX iwconfig ath0 ap XX:XX:XX:XX:XX:XX iwconfig ath0 channel X iwconfig ath0 essid foobar iwconfig ath0 rate XXMB
If you use debian, then the interfaces (in /etc/networks/interfaces used by ifup) commands would similarly be:
wireless_key XXXXXXXXXX wireless-ap XX:XX:XX:XX:XX:XX wireless-channel X wireless-essid foobar wireless-rate XXMB
Where all of the Xs and ‘foobar’s are replaced by relevant values. All of the values can be used in ifupdown-roam’s ‘lifaces’. Silas also says that it is not normally necessary to put the lines after iwconfig ath0 ap XX:XX:XX:XX:XX:XX since the channel, essid and rate are set automatically on sucessfully associating with an access point. Also note that you can’t copy the second set of commands into RedHat?’s config files verbatim; they are debian specific.
More information can be found in the archives here.
Notes for TEW-443PI - Atheros chip revision A1.1R under PC Linux OS (and maybe Mandriva)
Under PC Linux OPS which is a distro based on Mandriva you should setup under the harware options for your wireless card (Control Center -> Hardware -> Look at and configure harware) -> Set the current driver option: autocreate: mode of your wireless card.
For my Trendnet TEW-443PI with Atheros revision A1.1R works after I added in the Set current driver option the same mode used for the network.
Ex.: I wanted to use my card in an adhoc network between two computers. After added "adhoc" (without quotes) as option for autocreate, reboot. Then setup my network using wizard and the network works like a charm Before adding that option my card never want to work.