Re: NM and WEP

[Dan Williams <dcbw redhat com>]

On Fri, 2007-06-01 at 11:16 -0400, Derek Atkins wrote:
> Ryan Novosielski <novosirj umdnj edu> writes:
> 
> > I've found that no system seems to care whether you select open system
> > or shared key. Perhaps I always leave it on open. I've never seen
> > anyplace to set this on the other end, though, so I'm really in the dark
> > about what it does.
> 
> Then you haven't looked hard enough. ;)   It is a difference.
> I BELIEVE the difference is about the level of authentication
> or something, but I don't recall.  At one point many moons ago
> the madwifi driver was buggy in that it would only work on an
> Open System with 802.11(a).  IIRC, Shared Key is "more secure".

Right; if your access point only supports Open System authentication,
then setting Shared Key will fail association.  If your access point
only supports Shared Key, then setting Open System will fail
authentication.

Most consumer access points allow you to select (and default to) an
"auto" mode.  But some corporate systems still use Shared Key only.  WEP
provides _no_ way to autodetect what the correct auth method is, and
there's no indication in Open System+WEP that the WEP key is wrong.
Which means that to determine that a WEP-encrypted connection has
failed, you have to just try one and wait for the whole DHCP process to
time out.

Dan