802.11a/n

Grant emailgrant at gmail.com
Mon Aug 15 18:30:41 EDT 2011


>>> I'm using a Ubiquiti SR71-E 802.11abgn card and I've tried specifying
>>> many different channels for 802.11a mode but I always get this error:
>>>
>>> wlan0: IEEE 802.11 Configured channel (36) not found from the channel
>>> list of current mode (2) IEEE 802.11a
>>> wlan0: IEEE 802.11 Hardware does not support configured channel
>>
>> It sounds like your card could be calibrated as a world roaming card and
>> it does not allow AP mode to be started on 5 GHz channels. You can check
>> the available channel list with "iw list". The channels that are marked
>> "disabled" or "passive scanning" won't be available for hostapd to use
>> in AP mode.

A lot of the info I gave below is incorrect.  I've been switching
between a bg card and the SR71-E abgn card and I forgot which one I
had installed.  The SR71-E always lists both 2.4Ghz channels and 5Ghz
channels with 'iwlist wlan0 channel' but I always get the "Configured
channel not found from the channel list of current mode" error when
trying to start hostapd with a 5Ghz channel.

- Grant


> Something must be wrong with the config on my router.  I have two of
> these SR71-E cards, one in my laptop and one in my router.  The one in
> the laptop says:
>
> # dmesg|grep cfg80211
> ...
> cfg80211: Calling CRDA to update world regulatory domain
> cfg80211: Calling CRDA for country: US
> cfg80211: Calling CRDA to update world regulatory domain
> ...
> # iwlist wlan0 channel
> wlan0     20 channels in total; available frequencies :
>          Channel 01 : 2.412 GHz
>          Channel 02 : 2.417 GHz
>          Channel 03 : 2.422 GHz
>          Channel 04 : 2.427 GHz
>          Channel 05 : 2.432 GHz
>          Channel 06 : 2.437 GHz
>          Channel 07 : 2.442 GHz
>          Channel 08 : 2.447 GHz
>          Channel 09 : 2.452 GHz
>          Channel 10 : 2.457 GHz
>          Channel 11 : 2.462 GHz
>          Channel 36 : 5.18 GHz
>          Channel 40 : 5.2 GHz
>          Channel 44 : 5.22 GHz
>          Channel 48 : 5.24 GHz
>          Channel 149 : 5.745 GHz
>          Channel 153 : 5.765 GHz
>          Channel 157 : 5.785 GHz
>          Channel 161 : 5.805 GHz
>          Channel 165 : 5.825 GHz
>          Current Frequency:2.462 GHz (Channel 11)
>
> The one in the router says:
>
> # dmesg|grep cfg80211
> cfg80211: Calling CRDA to update world regulatory domain
> # iwlist wlan0 channel
> wlan0     14 channels in total; available frequencies :
>          Channel 01 : 2.412 GHz
>          Channel 02 : 2.417 GHz
>          Channel 03 : 2.422 GHz
>          Channel 04 : 2.427 GHz
>          Channel 05 : 2.432 GHz
>          Channel 06 : 2.437 GHz
>          Channel 07 : 2.442 GHz
>          Channel 08 : 2.447 GHz
>          Channel 09 : 2.452 GHz
>          Channel 10 : 2.457 GHz
>          Channel 11 : 2.462 GHz
>          Channel 12 : 2.467 GHz
>          Channel 13 : 2.472 GHz
>          Channel 14 : 2.484 GHz
>          Current Frequency:2.462 GHz (Channel 11)
>
> The thing is, I've tried switching them and the US card when installed
> into the router no longer says "cfg80211: Calling CRDA for country:
> US".  There must be some kind of a misconfig on the router but I don't
> know what it could be.  I think it used to work properly and stated
> CRDA US in dmesg on the router.  crda is installed and I have
> country_code=US in hostapd.conf.
>
> - Grant


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