On Fri, Mar 26, 2010 at 11:09 PM, Curtis Larsen <[email protected]> wrote: > On Fri, Mar 26, 2010 at 8:02 PM, Jouni Malinen > <[email protected]> wrote: >> On Fri, 2010-03-26 at 16:16 -0700, Pavel Roskin wrote: >>> I confirm that scan_freq is accepted by the current wpa_supplicant but >>> has no reliable effect. Both ath5k and ath9k connected to an AP on the >>> channel 6 when "scan_freq=2412" was in the configuration file. >> >> scan_freq is not supposed to limit the association to specific channels; >> it is only to limit scan requests made by wpa_supplicant. You may still >> find BSSes on other channels either due to scan requests made by other >> programs or by receiving Beacon/Probe Response frames on another >> channel. >> >> If there is interest for limiting the association to specific channels, >> it should be trivial addition to wpa_supplicant (with nl80211). > > Wireless vendors have started to realize the problem here and have > begun implementing features to help. An example from the latest Cisco > Controller configuration guide for 802.11n AP's: > > ...Configuring Band Selection > > The 2.4-GHz band is often congested. Clients on this band typically > experience interference from Bluetooth devices, microwave ovens, and > cordless phones as well as co-channel interference from other access > points because of the 802.11b/g limit of three non-overlapping > channels. To combat these sources of interference and improve overall > network performance, controller software release 6.0 enables you to > configure band selection on the controller. This feature enables > client radios that are capable of dual-band (2.4- and 5-GHz) operation > to move to a less congested 5-GHz access point... > >> I don't >> know whether I would fully agree on this being a useful thing for >> general use, but I can understand it at least as a testing tool > > Yes, how can one accurately simulate an end user problem when their > client is on a different band than yours and you have no control over > which band your client lands on. > >>(which >> people may then misuse for other things ;-). > > Years ago Intel (and I think some Broadcom) made that same decision > with many of their Windows drivers, and now recently Microsoft with > Vista and Windows 7 thought it was important enough to at least have > the option. Agreed ...it is not on the first page of the > configuration, but it is an option for those of us looking hard enough > to find it. > > ...Especially if it is "trivial" ...please consider adding. For me, > it's the only reason I occasionally have to boot Windows.
In case anyone else reads this thread... this feature is added in the current development tree. Thanks to Jouni I was able to get it working on ubuntu 9.10 by doing the following: 1- git clone git://w1.fi/srv/git/hostap.git 2- cd /home/clarsen/hostap/wpa_supplicant 3- copy defconfig to .config, then edit .config to enable nl80211 driver. 4 - Type make ...(this failed on first try and gave an error that something libdevel or some thing I can't remember was missing 5- Installed missing lib-devel package. 6- Typed make again - this time it finished compiling all the way through. 7- Added "freq_list =5825" to network config block 8- Typed sudo ./wpa_supplicant -c /etc/wpa_supplicant/WIFI.conf -i wlan0 -D nl80211 -d 9- Successfully connected to 5ghz radio as desired - (prior to this feature my client always chose 2.4Ghz). I can see in the wpa_supplicant output that shows it is *skipping* the "WIFI" SSID in the 2.4Ghz band: 0: 00:20:a6:49:a5:cb ssid='WIFI' wpa_ie_len=22 rsn_ie_len=0 caps=0x431 selected based on WPA IE skip - frequency not allowed 1: 00:20:a6:49:a5:ca ssid='WIFI' wpa_ie_len=22 rsn_ie_len=0 caps=0x411 selected based on WPA IE selected WPA AP 00:20:a6:49:a5:ca ssid='WIFI' So ...it seems to work great now! Thanks, Curtis _______________________________________________ ath9k-devel mailing list [email protected] https://lists.ath9k.org/mailman/listinfo/ath9k-devel
