XP "deauthenticate" after 802.1x authentication finished

Gunter Burchardt gbur at informatik.uni-rostock.de
Mon Aug 9 14:43:57 EDT 2004


> I encontered a very strange problem with following setting:
> 
>  Hostap driver 0.2.4, Linux2.4, and WindowsXP as a client. The problem comes when I
>  turn on i802.1x authentication by using freeradius. The authentication method
>  is PEAP and this problem seems have nothing to do with authentication method directly.
> 
>  In fact everything works pretty well. The i802.1x authentication works fine,
> but several seconds after the i802.1x authentication finishs, XP always sends
> out a "deauthentication" frame with reason code 3:(Station has left the basic
> service area..)

Background: After Authentication WindowsXP expects encryption keys for
the session. If it dont get one it disconnects!

Now the question why hostapd didn't send the keys. I guess you didn't
configure WEP keylen in hostapd.conf. If it is not configured hostapd
will not send WEP keys!

# WEP rekeying (disabled if key lengths are not set or are set to 0)
# Key lengths for default/broadcast and individual/unicast keys:
# 5 = 40-bit WEP (also known as 64-bit WEP with 40 secret bits)
# 13 = 104-bit WEP (also known as 128-bit WEP with 104 secret bits)
wep_key_len_broadcast=13
wep_key_len_unicast=13

regards
gunter

Please insert this stuff to the FAQ :)



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