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[SOLVED] Misterious wifi issue

Posted: 01 Aug 2017, 00:55
by fulalas
This is driving me crazy! My home wifi network suddenly isn't recognizable anymore only by my desktop + Porteus (any version/DE!).

1- if I boot into Windows or Live Ubuntu in the same computer, wifi works;
2- if I broadcast a wifi connection from my smartphone, wifi works;
3- if I insert my Porteus USB stick inside a laptop, wifi works;
4- if I boot on AF mode, wifi doesn't work;
5- if I try another kernel version, wifi doesn't work;
6- if I copy to a different USB stick a completely new Porteus ISO (x86 or x64!), wifi doesn't work;
7- if I remove NetworkManager/ModemManager/NetworkManagerApplet completely and put Connman instead, wifi still doesn't work;

So it seems that something specifically related to the combination Porteus + my desktop PC is causing the wifi to not be recognized. :unknown:

Misterious wifi issue

Posted: 01 Aug 2017, 04:39
by jssouza
Solution: Move to ubuntu :lol:

Seriously though, if wifi works on ubuntu, probably a firmware issue. Do you see anything interesting in dmesg? What is the wifi card and driver in use: lspci -knn?

Afterthought: Maybe the same lspci command on the working ubuntu might also help, to see if there is a difference...

Misterious wifi issue

Posted: 01 Aug 2017, 05:31
by fulalas
Hahahaha! Or even worse: Windows :crazy:

I forgot to say that I can connect with no problem to another wifi network (smartphone broadcast, for example) using Porteus. So there's no problem with kernel/wifi card. Also, I can't remember changing anything for this problem to happen -- it came out of nothing! It's like the router doesn't like Porteus + my PC anymore. WTF?! :fool:

Misterious wifi issue

Posted: 01 Aug 2017, 12:51
by donald
Q:
Do you see your network ( but can't connect) or is it not visible?

I once had the problem that the AP can use the (allowed) channels 1-13,
but the wifi card did only support channel 1-11.(country code)
If the AP switched to eg. 13 i was off.

Misterious wifi issue

Posted: 01 Aug 2017, 13:28
by fulalas
@donald, from my PC + Porteus I can't even see my AP wifi network (although I can see wifi networks broadcasted by a smartphone). And inside Windows/Ubuntu I can see and connect to my AP wifi network flawlessly, so I don't think there's no problem with the current AP channel (it's set to auto). What you think?

Misterious wifi issue

Posted: 01 Aug 2017, 14:16
by donald
try this:
Set your AP to a fixed channel e,g channel 6 ..

Misterious wifi issue

Posted: 01 Aug 2017, 14:51
by fulalas
@donald, you're the man! It worked! How is that possible if in Windows/Ubuntu the channel was the same? :-O

Misterious wifi issue

Posted: 01 Aug 2017, 15:12
by donald
Great...

-- how is this possible -- I think *buntu has the CRDA included -- porteus
has not..IIRC

I think you know it...but just in case - and for anyone else who reads this..
With a working connection in linux (e.g. *buntu)
iwlist channel will show which channel is used

Code: Select all

root@porteus:/home/guest# iwlist channel
lo        no frequency information.

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:2.437 GHz (Channel 6)
Use the same command in porteus to determine the capability of the wifi card/dongle

Misterious wifi issue

Posted: 01 Aug 2017, 16:04
by fulalas
Hmmmm... I though that the channel was something that only the AP could change. :o

Misterious wifi issue

Posted: 01 Aug 2017, 16:39
by donald
That's correct, but the wifi card must be able to follow the decision the AP has made.
Almost every wifi card/dongle is internally branded
with a fixed country code (like CN,US,DE).
This country code limits the wifi to the channels (and output) which are
allowed in this country.
Example:
My (older) usb wifi had the country code CN which allowed only channel 1-11 but
in Germany one is allowed to use channel 1-13.
To overcome this issue, there is the CRDA regulatory bin which being called does
set the correct country code (values) for your country - DE in my case - so i can use
the channels 12,13 too.
If you want to check which CC is internally used, install "iw" and invoke

Code: Select all

root@porteus:/home/guest# iw reg get

[SOLVED] Misterious wifi issue

Posted: 05 Aug 2017, 22:13
by brokenman
Another slam dunk by donald!

[SOLVED] Misterious wifi issue

Posted: 06 Aug 2017, 15:33
by donald
:) When the last post is made by you the number of readers increases rapidly. :)

[SOLVED] Misterious wifi issue

Posted: 06 Aug 2017, 16:11
by jssouza
Thanks donald, but 5GHz is much much more complex.

UNII3 in EU is 25mhz (ISM) band, while unii3 in US is 4 Watts (according to latest FCC)..

That would mean, Wlan channels 149 to 165 have a transmission power of 25mhz in the EU, but it has a transmission power of 4W in the US. Do you agree?

[SOLVED] Misterious wifi issue

Posted: 06 Aug 2017, 16:36
by donald
Hi jssouza
Personally i don't use the 5GHz band because the signal penetrates walls badly.

allowed tx power:
https://w.wol.ph/2015/08/28/maximum-wif ... r-country/

If your card is able to use higher tx power, you can (but shouldn't)
set higher values in the regulatory.bin
THIS WOULD BE ILLEGAL -- NOT RECOMMENDED - but possible.

[SOLVED] Misterious wifi issue

Posted: 06 Aug 2017, 17:15
by jssouza
donald wrote:
06 Aug 2017, 16:36
Hi jssouza
Personally i don't use the 5GHz band because the signal penetrates walls badly
Thnaks donald, yes, it does have lower penetration capabilities than that of 2.4GHz (because of the lower wavelength). But, I think we can over come that with a directional antenna with a higher EIRP, what do you think?
Also, because, it does not have a higher sensitivity than that of a 2.4 GHz, in big events (like the Kölner Lichter) , the interference (from eg: the ship that carries the fireworks) is lower, what do you think?