Discussion:
Wifi scanner for FreeBSD
Matthias Apitz
2021-04-04 08:23:24 UTC
Permalink
Hello,

On my Ubuntu based cellphone (BQ E4.5, https://ubports.com) I have a
Wifi scanner app, a picture how it looks like is here:
Loading Image...
"tarara" is my AP in my house in about 900 meter distance.

Do we have something similar for our beloved FreeBSD in our ports
collection?

Thanks

matthias
--
Matthias Apitz, ✉ ***@unixarea.de, http://www.unixarea.de/ +49-176-38902045
Public GnuPG key: http://www.unixarea.de/key.pub
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matti k
2021-04-04 08:57:13 UTC
Permalink
On Sun, 4 Apr 2021 10:23:24 +0200
Post by Matthias Apitz
Hello,
On my Ubuntu based cellphone (BQ E4.5, https://ubports.com) I have a
https://forums.ubports.com/assets/uploads/files/1615713748334-wifi-bank-900m.jpg
"tarara" is my AP in my house in about 900 meter distance.
Do we have something similar for our beloved FreeBSD in our ports
collection?
Thanks
matthias
Hi mathius

One can also display the current list of known networks with:

# ifconfig wlan0 list scan

reference:
https://docs.freebsd.org/en_US.ISO8859-1/books/handbook/network-wireless.html

Cheers,

Matti
Matthias Apitz
2021-04-04 09:18:12 UTC
Permalink
Post by matti k
# ifconfig wlan0 list scan
After 25 years with FreeBSD, I'm aware of this man page :-)
I was asking for a graphical monitor.

matthias
--
Matthias Apitz, ✉ ***@unixarea.de, http://www.unixarea.de/ +49-176-38902045
Public GnuPG key: http://www.unixarea.de/key.pub
¡Con Cuba no te metas! «» Don't mess with Cuba! «» Leg Dich nicht mit Kuba an!
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LuMiWa via freebsd-questions
2021-04-04 10:00:24 UTC
Permalink
On Sun, 4 Apr 2021 11:18:12 +0200
Post by Matthias Apitz
Post by matti k
# ifconfig wlan0 list scan
After 25 years with FreeBSD, I'm aware of this man page :-)
I was asking for a graphical monitor.
matthias
I did try net-mgmt/networkmgr but it didn't work. There is also wifimgr and I didn't try
--
“We live in a world where there is more and more information, and less
and less meaning.”

Jean Baudrillard
Jacques Foucry
2021-04-04 10:03:27 UTC
Permalink
Post by Matthias Apitz
Post by matti k
# ifconfig wlan0 list scan
After 25 years with FreeBSD, I'm aware of this man page :-)
I was asking for a graphical monitor.
Look at net-mgmt/wifimgr
--
Jacques Foucry
matti k
2021-04-04 10:45:12 UTC
Permalink
On Sun, 4 Apr 2021 12:03:27 +0200
Post by Jacques Foucry
Post by Matthias Apitz
Post by matti k
# ifconfig wlan0 list scan
After 25 years with FreeBSD, I'm aware of this man page :-)
I was asking for a graphical monitor.
Look at net-mgmt/wifimgr
hi again :-)

I am using networkmgr-4.5 with XFCE / maybe some gnome bits

https://imgur.com/a/J6HIGpZ

Maybe it helps from the GUI perspective!

Cheers,

Matti


Happy Easter and enjoy !!
Ralf Mardorf
2021-04-04 11:35:36 UTC
Permalink
Post by matti k
https://imgur.com/a/J6HIGpZ
It does show "available" networks, but not transmitting
capacity. Due to digitalisation of elementary schools in Germany,
enforced by the coronavirus pandemic, as somebody working for after
school childcare, a teacher and I set up LTE wifi routers and iPads.
That a network is displayed, doesn't mean that you get a reliable
connection. The school has got 5 routers and IIRC 25 iPads +
several other receivers (a digital board, smartphones and a TV).

I described my private network and mentioned that "I would be surprised
to see it in about a 9 meter distance". Actually it most likely is
recognized by devices >= 9 meters away, but it's unlikely usable at
this distance.

The forums link provided by Matthias, see
https://lists.freebsd.org/pipermail/freebsd-questions/2021-April/293682.html
mentions why it's a tricky subject.

In school those iPads show powerful access to the LTE wifi routers, but
often the closest routers isn't usable, while a less close router can
be used, at least with a single iPad, dunno if it stands the traffic of
all the iPads.

The graphic provided by Matthias' Ubuntu based cellphone shows an
amazing transmitting capacity spike. It could be important to actually
get such information, not only for wifi. Depending on atmospheric
condition, there could be e.g. interferences between DVB-T
transmitters. Too powerful signals could become a PITA for somebody who
wants to watch television, OTOH amateur radio operators might welcome
such atmospheric conditions ;).

Getting a list without reliable information about the power is quite
useless. iPads for example provide a graphic showing 3 lines. Usually 3
and 2 lines are for a good connection and even 1 line still could be
reliable. At home 2 lines are ok for me, in school those lines mean
absolutely nothing. You could get those lines, but the connection still
could be fishy.
Peter Cornelius
2021-04-05 07:12:27 UTC
Permalink
G'day, folks,
 
Regarding the first post, I would not mind to see such application in ports myself though I think that the mobile apps suggest more than they hold.
 
Regarding 2.4 GHz WiFi, I have come to the conclusion that I will avoid that band with WiFi wherever I can. I have the experience from my earlier place in town where I was able to see the beacons of the order of 50 wlans, that a single station not on one of the non-overlapping bands [1] causes so much interference to all on one of the non-overlapping ones that there is no throughput at all for anyone. I don't know what kind of pot people had when they invented that standard, but that's how it is.
 
When you use such 'free' channel (as in the image at the mail starting this thread), all that happens is that you can't decode the others, and the others can't decode your emissions but you very effectively interfere with each other, making the entire spectrum unusable. And all the blue teeth and other emissions on that band just add to that.
 
In short, if all stick to the non-overlapping channels (and do not bundle), one may get some throughput as the protocol can control the channel. If one deviates, forget it.
 
Just my 2 cents.
 
Cheers,
 
Peter.
 
[1] https://en.wikipedia.org/wiki/List_of_WLAN_channels
 


 

Gesendet: Sonntag, 04. April 2021 um 13:35 Uhr
Von: "Ralf Mardorf" <ralf-***@riseup.net>
An: freebsd-***@freebsd.org
Betreff: Re: Wifi scanner for FreeBSD
Post by matti k
https://imgur.com/a/J6HIGpZ
It does show "available" networks, but not transmitting
capacity. Due to digitalisation of elementary schools in Germany,
enforced by the coronavirus pandemic, as somebody working for after
school childcare, a teacher and I set up LTE wifi routers and iPads.
That a network is displayed, doesn't mean that you get a reliable
connection. The school has got 5 routers and IIRC 25 iPads +
several other receivers (a digital board, smartphones and a TV).

I described my private network and mentioned that "I would be surprised
to see it in about a 9 meter distance". Actually it most likely is
recognized by devices >= 9 meters away, but it's unlikely usable at
this distance.

The forums link provided by Matthias, see
https://lists.freebsd.org/pipermail/freebsd-questions/2021-April/293682.html[https://lists.freebsd.org/pipermail/freebsd-questions/2021-April/293682.html]
mentions why it's a tricky subject.

In school those iPads show powerful access to the LTE wifi routers, but
often the closest routers isn't usable, while a less close router can
be used, at least with a single iPad, dunno if it stands the traffic of
all the iPads.

The graphic provided by Matthias' Ubuntu based cellphone shows an
amazing transmitting capacity spike. It could be important to actually
get such information, not only for wifi. Depending on atmospheric
condition, there could be e.g. interferences between DVB-T
transmitters. Too powerful signals could become a PITA for somebody who
wants to watch television, OTOH amateur radio operators might welcome
such atmospheric conditions ;).

Getting a list without reliable information about the power is quite
useless. iPads for example provide a graphic showing 3 lines. Usually 3
and 2 lines are for a good connection and even 1 line still could be
reliable. At home 2 lines are ok for me, in school those lines mean
absolutely nothing. You could get those lines, but the connection still
could be fishy.
_______________________________________________
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Valeri Galtsev
2021-04-05 13:29:30 UTC
Permalink
Post by Peter Cornelius
G'day, folks,
Regarding the first post, I would not mind to see such application in ports myself though I think that the mobile apps suggest more than they hold.
Regarding 2.4 GHz WiFi, I have come to the conclusion that I will avoid that band with WiFi wherever I can. I have the experience from my earlier place in town where I was able to see the beacons of the order of 50 wlans, that a single station not on one of the non-overlapping bands [1] causes so much interference to all on one of the non-overlapping ones that there is no throughput at all for anyone. I don't know what kind of pot people had when they invented that standard, but that's how it is.
There is one more rationale to avoid 2.4 GHz band: there are commodity devices that create strong interference in this band: microwave ovens, cordless phones.

However, if you are in the building with “wet” wall (any construction material that may host water: most notably brick, concrete), then 5 GHz will work on much closer range than 2.4 GHz: higher rf frequencies are more efficiently absorbed by construction materials.

I hope, this helps.

Valeri
Post by Peter Cornelius
When you use such 'free' channel (as in the image at the mail starting this thread), all that happens is that you can't decode the others, and the others can't decode your emissions but you very effectively interfere with each other, making the entire spectrum unusable. And all the blue teeth and other emissions on that band just add to that.
In short, if all stick to the non-overlapping channels (and do not bundle), one may get some throughput as the protocol can control the channel. If one deviates, forget it.
Just my 2 cents.
Cheers,
Peter.
[1] https://en.wikipedia.org/wiki/List_of_WLAN_channels
Gesendet: Sonntag, 04. April 2021 um 13:35 Uhr
Betreff: Re: Wifi scanner for FreeBSD
Post by matti k
https://imgur.com/a/J6HIGpZ
It does show "available" networks, but not transmitting
capacity. Due to digitalisation of elementary schools in Germany,
enforced by the coronavirus pandemic, as somebody working for after
school childcare, a teacher and I set up LTE wifi routers and iPads.
That a network is displayed, doesn't mean that you get a reliable
connection. The school has got 5 routers and IIRC 25 iPads +
several other receivers (a digital board, smartphones and a TV).
I described my private network and mentioned that "I would be surprised
to see it in about a 9 meter distance". Actually it most likely is
recognized by devices >= 9 meters away, but it's unlikely usable at
this distance.
The forums link provided by Matthias, see
https://lists.freebsd.org/pipermail/freebsd-questions/2021-April/293682.html[https://lists.freebsd.org/pipermail/freebsd-questions/2021-April/293682.html]
mentions why it's a tricky subject.
In school those iPads show powerful access to the LTE wifi routers, but
often the closest routers isn't usable, while a less close router can
be used, at least with a single iPad, dunno if it stands the traffic of
all the iPads.
The graphic provided by Matthias' Ubuntu based cellphone shows an
amazing transmitting capacity spike. It could be important to actually
get such information, not only for wifi. Depending on atmospheric
condition, there could be e.g. interferences between DVB-T
transmitters. Too powerful signals could become a PITA for somebody who
wants to watch television, OTOH amateur radio operators might welcome
such atmospheric conditions ;).
Getting a list without reliable information about the power is quite
useless. iPads for example provide a graphic showing 3 lines. Usually 3
and 2 lines are for a good connection and even 1 line still could be
reliable. At home 2 lines are ok for me, in school those lines mean
absolutely nothing. You could get those lines, but the connection still
could be fishy.
_______________________________________________
https://lists.freebsd.org/mailman/listinfo/freebsd-questions[https://lists.freebsd.org/mailman/listinfo/freebsd-questions]
_______________________________________________
https://lists.freebsd.org/mailman/listinfo/freebsd-questions
Matthias Apitz
2021-04-06 11:49:16 UTC
Permalink
Post by Peter Cornelius
G'day, folks,
 
Regarding the first post, I would not mind to see such application in ports myself though I think that the mobile apps suggest more than they hold.
 
Regarding 2.4 GHz WiFi, I have come to the conclusion that I will avoid that band with WiFi wherever I can. I have the experience from my earlier place in town where I was able to see the beacons of the order of 50 wlans, that a single station not on one of the non-overlapping bands [1] causes so much interference to all on one of the non-overlapping ones that there is no throughput at all for anyone. I don't know what kind of pot people had when they invented that standard, but that's how it is.
 
When you use such 'free' channel (as in the image at the mail starting this thread), all that happens is that you can't decode the others, and the others can't decode your emissions but you very effectively interfere with each other, making the entire spectrum unusable. And all the blue teeth and other emissions on that band just add to that.
 
In short, if all stick to the non-overlapping channels (and do not bundle), one may get some throughput as the protocol can control the channel. If one deviates, forget it.
 
Hi Peter,

The AP at home has only support for 2.4 GHz and my devices (FreeBSD laptops,
Linux laptops and a bunch of E4.5 Ubuntu cellphones) perhaps also only
for 2.4 GHz.

Which channel you would suggest?

The question has todo with one of the BQ E4.5 Ubuntu cellphones
I have here in my family: It connects fine with *any* AP outside my house
(in my company, public APs and even using my iPhone 8 as AP in personal
hotspot mode). But it does not work with the AP in question. It
connects, get an IP assigned but traffic to/from get stuck. Maybe some
interference which affects only this device. It was not always this way,
it started from one day to the other...

Thanks for any hint what I could do.


matthias
--
Matthias Apitz, ✉ ***@unixarea.de, http://www.unixarea.de/ +49-176-38902045
Public GnuPG key: http://www.unixarea.de/key.pub
¡Con Cuba no te metas! «» Don't mess with Cuba! «» Leg Dich nicht mit Kuba an!
http://www.cubadebate.cu/noticias/2020/12/25/en-video-con-cuba-no-te-metas/
Peter Cornelius
2021-04-07 09:32:58 UTC
Permalink
Hola Matthias, muy buen dia,
 
Post by Matthias Apitz
Which channel you would suggest?
That depends. On your environment, the neighbourhood of APs (and probably a lot of other radiating sources in your area as others have pointed out).
If you only look at WiFi, however, channels 1, 5, 9, and 13 may be a good choice -- if you use 802.11g/n and no one else nearby is on 802.11b or n only ([1], [2], and assuming that you're in the EU).
Post by Matthias Apitz
Thanks for any hint what I could do.
That is difficult but maybe you can tell the phone not to attempt to go up to bandwidths above a certain bandwidth, or tell the AP not to. That reduces throuhgput but may lead to more stable connections in a noisy or edge-case environment. Other than that, I'd also be pretty much out of ideas, sorry.

Saludos,

Peter.

[2] https://upload.wikimedia.org/wikipedia/commons/8/84/NonOverlappingChannels2.4GHzWLAN-en.svg

---

Gesendet: Dienstag, 06. April 2021 um 13:49 Uhr
Von: "Matthias Apitz" <***@unixarea.de>
An: "Peter Cornelius" <***@gmx.net>
Cc: freebsd-***@freebsd.org
Betreff: Re: Re: Wifi scanner for FreeBSD
El día lunes, abril 05, 2021 a las 09:12:27a. m. +0200, Peter Cornelius escribió:

Hi Peter,

The AP at home has only support for 2.4 GHz and my devices (FreeBSD laptops,
Linux laptops and a bunch of E4.5 Ubuntu cellphones) perhaps also only
for 2.4 GHz.

Which channel you would suggest?

The question has todo with one of the BQ E4.5 Ubuntu cellphones
I have here in my family: It connects fine with *any* AP outside my house
(in my company, public APs and even using my iPhone 8 as AP in personal
hotspot mode). But it does not work with the AP in question. It
connects, get an IP assigned but traffic to/from get stuck. Maybe some
interference which affects only this device. It was not always this way,
it started from one day to the other...

Thanks for any hint what I could do.


matthias
--
Matthias Apitz, ✉ ***@unixarea.de, http://www.unixarea.de/ +49-176-38902045
Public GnuPG key: http://www.unixarea.de/key.pub[http://www.unixarea.de/key.pub]
¡Con Cuba no te metas! «» Don't mess with Cuba! «» Leg Dich nicht mit Kuba an!
http://www.cubadebate.cu/noticias/2020/12/25/en-video-con-cuba-no-te-metas/[http://www.cubadebate.cu/noticias/2020/12/25/en-video-con-cuba-no-te-metas/]
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