How to use a util like linssid without connecting to my router

maggie · 2013-06-16 12:31:08

I found linssid in the AUR and use it to see the wireless landscape around me. How can I use it without connecting to a wireless router? I would like to just bring up my wireless NIC but not connect. How can I do this? I use netctl with a wireless-wap profile to connect to my router by the way. Thanks!

Strike0 · 2013-06-16 12:44:43

You stop your netctl connection (if active), make sure the wireless interface is up with

iw link set <wlan0> up

and the linssid tool should work like that.

maggie · 2013-06-16 12:59:53

That is not working. My LAN is enp0s9 and my wireless is wlp2s0. I did your comment but iw just threw errors.

% sudo iw link set wlp2s0 up  
Usage:	iw [options] command
Options:
	--debug		enable netlink debugging
	--version	show version (3.10)
...
...

Last edited by maggie (2013-06-16 19:34:56)

Strike0 · 2013-06-16 13:21:51

Sorry, my bad. We were to use "ip", not "iw":

sudo ip link set up dev wlp2s0
sudo ip link set wlp2s0 up

both do it.

Last edited by Strike0 (2013-06-16 13:25:33)

maggie · 2013-06-16 17:35:11

Thanks for the reply. For me, neither of them work. For example.

% sudo ip link set wlp2s0 up
%
% ip addr
2: wlp2s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN qlen 1000
    link/ether 00:01:ac:e5:63:db brd ff:ff:ff:ff:ff:ff

Last edited by maggie (2013-06-16 19:34:32)

Strike0 · 2013-06-16 19:11:19

Bit odd yes. I'm not sure off my head why the state might show as down in your output, but in the brackets there is the UP. After that command you should be able to let it scan scan the networks yourself. Does that not work?

maggie · 2013-06-16 19:34:07

Can both the wired and wireless be used at the same time? I do not want to connect with my wireless, just scan. I do want to stay connected on the wired while scanning.

Strike0 · 2013-06-16 19:43:52

Sure, you can also be connected with both and still scan. The scan info is needed anyway by the wifi devices so they avoid interference or for features like roaming.

edit: edit for rememberance as I just see this is my triple-infinite-loop post #888

Last edited by Strike0 (2013-06-16 19:50:42)

graysky · 2013-06-16 20:35:58

There is nothing wrong with what you're doing; it would seem that linssid requires you to be connected to a wireless network for some reason. Try the command Strike0 suggested and use wiki-radar (in [community]) and you will see that it works while you're connected via a hardline.

On my workstation:

% sudo ip link set wlp7s0 up
% sudo wifi-radar

Last edited by graysky (2013-06-16 20:36:32)

Trilby · 2013-06-16 20:42:37

If you don't need the big gui, that just looks like a frontend for a `iwlist scan` anyways, which doesn't require a connection.

(why would you need an active wireless connection to get a list of available networks ... that's like needing a cart to get a horse)

graysky · 2013-06-16 20:47:25

Trilby wrote:

If you don't need the big gui, that just looks like a frontend for a `iwlist scan` anyways, which doesn't require a connection.

Yes, it is a GUI for that command you reference, but that command's output is pretty verbose (300+ lines for me). The GUI is a nice compact window with nice icons, etc.

Trilby wrote:

(why would you need an active wireless connection to get a list of available networks ... that's like needing a cart to get a horse)

I don't think so in this case. If I attempt either `sudo wifi-radar` or `sudo iwlist scan` without first initializing the card with a `sudo ip link set wlp7s0 up` I get errors.

Example:

% sudo iwlist scan
eno1      Interface doesn't support scanning.

wlp7s0    Interface doesn't support scanning : Network is down

lo        Interface doesn't support scanning.

Dunno what that means for your cart/horse simile

Last edited by graysky (2013-06-16 20:48:46)

Trilby · 2013-06-16 20:50:03

the interface needs to be up, but you don't need a connection. One needs to know what connections are available *before* they can connect ... unless one is psychic.

This is actually one of the reasons I encourage new users to learn the manual connection steps. Networking tools hide a lot of these steps and work by 'magic'. The networking tools have no magic, they just bring up the interface, scan for available connections, *then* connect.

Last edited by Trilby (2013-06-16 20:51:59)

graysky · 2013-06-16 20:51:47

@op - Did this conversation solve your problem? Seems as though the answer to the thread's title is "you cannot."

maggie · 2013-06-17 19:38:45

I will not mark it for a few days in case someone else shows me the solution. It seems like it should not need to connect to a SSID to measure the surrounding networks.

Trilby · 2013-06-17 20:23:49

It should not need to be - there is no reason for it what so ever. But that is how it is currently written. You can request the author change that*, but aside from patching the source code, there is not going to be any magic bullet to make that program work.

*Awesome quick response from the author (below) - I may have to try this out now.

Last edited by Trilby (2013-06-22 14:14:25)

Strike0 · 2013-06-17 22:40:32

Exactly.
But something else you might try is connect to your own wifi to let it measure, but use your wired connection as default route for your network activities. You should only have to adjust your wifi-connection for that (no default route, ignore dns, etc.).

edit: at least I assume so, i have not heard of the tool before and it does appear to be a bit goofy with that required connection. edit2: Certainly not goofy, since it turns out maggie caught a bug. Great of you to join the forum to clarify it, wseverin!

Last edited by Strike0 (2013-06-22 19:30:06)

wseverin · 2013-06-21 23:32:19

Humm... Looks like a bug has appeared. I had to rewrite the section of code that looks for wifi interfaces to get around the earlier bug. Perhaps I have unwittingly introduced a new one. I'll be taking a look at it. I agree, it should allow scanning without having to have a connection!!
-Warren

graysky · 2013-06-22 14:10:12

@wseverin - Glad to play with the git version, but the repo appears to be empty. Are you not using git?

% git clone git://git.code.sf.net/p/linssid/code linssid-code 
Cloning into 'linssid-code'...
warning: You appear to have cloned an empty repository.

wseverin · 2013-06-22 15:37:52

So far have not been using git 'cause the source code, indeed the whole build package, is directly downloadable from sourceforge. I'll put git on the to-do list.

maggie · 2013-06-22 16:32:55

It is nice to see the dev came to our forums I would also like to see a git package thank you. Also thank you for linssid. I love it.

wseverin · 2013-06-23 06:34:48

I posted LinSSID version 2.1 to sourceforge and launchpad today. With a bit of luck the change will fix much of the problem with nondiscovery of interfaces that are 'up' but not 'connected'.

The problem, as with many recently, has its roots in the changeover from legacy WEXT drivers and utilities to NL80211 drivers and utilities. WiFi drivers tend to be problematic in how well they support either format. It's a haphazard mix. Most WiFi card/dongle providers base their drivers on the base drivers provided by the chipset manufacturers. Those drivers are inconsistent from one chipset manufacturer to another, and even among different drivers supplied by the same chipset manufacturers. In this case, some drivers report the existance of their interface through the WEXT utilities, some through the NL80211 utilities, and some both; and differing by whether the user is 'root' or another user, and by whether the interface is 'connected' or not. LinSSID 2.1 checks both sets of utilities as root and eliminates redundant reporting. Hopefully that will catch most of the failures.

Please let me know how it works for you.

Arch Linux

#1 2013-06-16 12:31:08

How to use a util like linssid without connecting to my router

#2 2013-06-16 12:44:43

Re: How to use a util like linssid without connecting to my router

#3 2013-06-16 12:59:53

Re: How to use a util like linssid without connecting to my router

#4 2013-06-16 13:21:51

Re: How to use a util like linssid without connecting to my router

#5 2013-06-16 17:35:11

Re: How to use a util like linssid without connecting to my router

#6 2013-06-16 19:11:19

Re: How to use a util like linssid without connecting to my router

#7 2013-06-16 19:34:07

Re: How to use a util like linssid without connecting to my router

#8 2013-06-16 19:43:52

Re: How to use a util like linssid without connecting to my router

#9 2013-06-16 20:35:58

Re: How to use a util like linssid without connecting to my router

#10 2013-06-16 20:42:37

Re: How to use a util like linssid without connecting to my router

#11 2013-06-16 20:47:25

Re: How to use a util like linssid without connecting to my router

#12 2013-06-16 20:50:03

Re: How to use a util like linssid without connecting to my router

#13 2013-06-16 20:51:47

Re: How to use a util like linssid without connecting to my router

#14 2013-06-17 19:38:45

Re: How to use a util like linssid without connecting to my router

#15 2013-06-17 20:23:49

Re: How to use a util like linssid without connecting to my router

#16 2013-06-17 22:40:32

Re: How to use a util like linssid without connecting to my router

#17 2013-06-21 23:32:19

Re: How to use a util like linssid without connecting to my router

#18 2013-06-22 14:10:12

Re: How to use a util like linssid without connecting to my router

#19 2013-06-22 15:37:52

Re: How to use a util like linssid without connecting to my router

#20 2013-06-22 16:32:55

Re: How to use a util like linssid without connecting to my router

#21 2013-06-23 06:34:48

Re: How to use a util like linssid without connecting to my router

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