Questions with wep keys for WinXP

[Jouni Malinen]

On Tue, Jun 24, 2003 at 02:39:47AM +0000, Haidong Xia wrote:

> Now, if I turn both of broadcast_key, and individual key on, and have the 
> workaround set to 1, my Exp
> setup works prefect.

You should _not_ use workaround if you enable both broadcast and
individual keys.

> I tried another way also. If I turn the individual key on, and default wep 
> key off.  WinXP only receives
> the unicast key after authentication succeeds. This is what I expected. But 
> WinXP client CAN NOT get
> an ip address through DHCP.  Since a DHCP request is a broadcast, I doubt 
> if something is wrong with the broadcast key.

hostapd does not support such configuration. You can either use only
broadcast key (which may require workaround with WinXP) or both
broadcast and unicast.

> So, if WinXP doesn't receive a broadcast key, will it use the only unicast 
> key to encrypt a DHCP request?

IEEE 802.11 stations do not actually send broadcast (.11) packets in
BSS. Only AP is sending broadcast packets. The destination address (DA)
of that packet is broadcast, but in STA->AP direction, the "802.11
destination" (addr1) is BSSID and the packet is unicast.. However, when
AP re-broadcasts this frame, it would be a real broadcast (.11) frame.

-- 
Jouni Malinen                                            PGP id EFC895FA