[root@localhost network-scripts]# iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

wmaster0  no wireless extensions.

wlan0     IEEE 802.11g  ESSID:"Valentin"  
          Mode:Managed  Frequency:2.412 GHz  Access Point: Not-Associated   
          Tx-Power=27 dBm   
          Retry min limit:7   RTS thr:off   Fragment thr=2346 B   
          Encryption key:<too big>
          Link Quality:0  Signal level:0  Noise level:0
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

[root@localhost network-scripts]# ifup wlan0
SIOCSIFFLAGS: No such file or directory

Determining IP information for wlan0...SIOCSIFFLAGS: No such file or directory
SIOCSIFFLAGS: No such file or directory