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Ticket #2264 (new defect)

Opened 13 years ago

Last modified 13 years ago

unexpected channel change - just scanning for ap?

Reported by: gynsty@yahoo.com Assigned to:
Priority: major Milestone:
Component: madwifi: other Version: trunk
Keywords: unexpected channel change Cc:
Patch is attached: 0 Pending: 0

Description

Hi,

I have this cards:

Atheros Communications Inc. AR5418 802.11abgn Wireless PCI Express Adapter

currenty using madwifi drivers trunk revision 3952,

compiled for kernel 2.6.18-92.1.22.el5 Centos 5.2 .

I have the issue with interface if set in STA mode. Look for this strange behaviour:

iwconfig ath0 channel 1
iwconfig ath0
ath0      IEEE 802.11a  ESSID:""  
          Mode:Managed  Frequency:2.412 GHz  Access Point: Not-Associated   
          Bit Rate:0 kb/s   Tx-Power:16 dBm   Sensitivity=1/1  
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=0/70  Signal level=-96 dBm  Noise level=-96 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

Interface set in 802.11a and on frequency 2.412Ghz (channel 1)!?

The main issue is that everytime I use commands:

iwconfig ath0 channel 1
iwconfig ath0 essid rocky
iwconfig ath0 ap 00:14:6C:7E:40:80
ifconfig ath0 up

Created interface ath0 starts to hop on channels including 802.11a, see this:

(no scanner such kismet or airodump is enabled on machine. )

iwconfig ath0       
ath0      IEEE 802.11g  ESSID:"rocky"  
          Mode:Managed  Frequency:2.422 GHz  Access Point: 00:14:6C:7E:40:80
          Bit Rate:0 kb/s   Tx-Power:19 dBm   Sensitivity=1/1  
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:626C-6166-6F   Security mode:restricted
          Power Management:off
          Link Quality=0/70  Signal level=-96 dBm  Noise level=-96 dBm
          Rx invalid nwid:15512  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

second later...
iwconfig ath0 
ath0      IEEE 802.11Ta  ESSID:"rocky"  
          Mode:Managed  Frequency:5.29 GHz  Access Point: 00:14:6C:7E:40:80 
          Bit Rate:0 kb/s   Tx-Power:16 dBm   Sensitivity=1/1  
          Retry:off   RTS thr:off   Fragment thr:off
          Encryption key:626C-6166-6F   Security mode:restricted
          Power Management:off
          Link Quality=0/70  Signal level=-93 dBm  Noise level=-93 dBm
          Rx invalid nwid:15512  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

So device just do not sit on channel but hops, looking for what??

So I already worked with madwifi drivers, but I never had such issue.

I already read ticket 572:

which mentions: "When we put "iwconfig ath0 channel 10", the sta will stop jumping channels, and stick with the one given (correct ?)"

Thas is exactly what I expect.. but.. it just does not work that way for me.

I have another atheros card with chipset AR5212/AR5213 but behaviour is the same all the time.

Best for you All

Change History

05/14/09 02:44:39 changed by tsharples

This seems to be standard behavior with 9.3.3 and up. Setting the channel on a STA device is ignored. The best you can probably do is use athchans to limit the range of channel-scanning behavior. Interestingly enough, we have seen occasions where even tho the STA is scanning as you describe, it won't actually associate with an AP on channel x until you issue the "iwconfig ath0 channel x" command.