[Solved] Some wifi networks connects, some don't

eduardowoj · 2014-01-15 16:16:37

Hello, it's my first time posting here! I installed Arch some days ago coming from Fedora, and I'm loving it!

Except for one thing.

Altough my post's title may sound quite cryptic, I didn't knew how to explain it better. I can connect to my home wireless AP, to the AP at my girlfriend's house, but I can't connect to the APs at my university! I checked every configuration, everything is identical to what I used to have on Fedora. And to make it more strage, I can connect to the wifi on Windows, withouth any lag or problem. I can connect through a ethernet cable (but today the cabled infrastructure is down, with everyone), it is only the wifi that is driving me mad. When I click to connect to a wifi network, two KDE notifications pop up:

"Wireless interface wlan0 - The WiFi network could not be found"
"Connection (connection name) disconnected"

I'm posting this through Windows, and I wrote down the outputs of some commands in a piece of paper to post it here. My laptop is a Lenovo Thinkpad T420

lspci -nn:

03:00 Network Controller: Intel Corporation Centrino Advanced-N 6205 [Taylor Peak] (Rev 34)
Subsystem: Intel Corportation Centrino Advanced-N 6205 AGN
Kernel driver in use: iwlwifi
Kernel modules: iwlwifi

ip link: wlan0: <NO-CARRIER, BROADCAST, MULTICAST, UP> mtu 1500 qdisc mq state DOWN mode DORMANT group default qlen 1000
link/ether (ip) brd ff:ff:ff:ff:ff:ff

I tried

ip link set wlan0 up

, but I couldn't bring the state to UP, it stayed on DOWN.

The relevant lines on dmesg shows me this:

IPV6 addrconf(netdev_up) wlan0 link is not ready
wlan0: authenticate with (access point ip)
wlan0: Direct probe to (access point ip) (try 1/3)
wlan0: Direct probe to (access point ip) (try 2/3)
wlan0: Direct probe to (access point ip) (try 3/3)
wlan0: Authentication with (access point ip) timed out

Any clues?

Last edited by eduardowoj (2014-01-27 10:51:41)

ewaller · 2014-01-15 16:41:22

What happens if you disable IPv6?
https://wiki.archlinux.org/index.php/IPv6#Disable_IPv6

eduardowoj · 2014-01-15 17:09:10

I disabled IPv6 by creating the /etc/sysctl.d/40-ipv6.conf file as your link suggested, but I've got the same dmesg messages and KDE notifications as before.

WonderWoofy · 2014-01-15 17:49:51

Did you just create that sysctl.d file, or did you actually apply those settings as well? The mere creation of the file will do nothing until you either reboot, or apply those settings with /usr/bin/sysctl.

eduardowoj · 2014-01-15 18:10:11

WonderWoofy wrote:

Did you just create that sysctl.d file, or did you actually apply those settings as well? The mere creation of the file will do nothing until you either reboot, or apply those settings with /usr/bin/sysctl.

After creating the file I rebooted, but nothing yet... I'm still getting the same messages.

WonderWoofy · 2014-01-15 18:18:02

Okay, just making sure.

Have you tried connecting manually with wpa_supplicant/wpa_passphrase and dhcpcd directly? That might yeild a bit more information as to what might be going on there. Also, is the university's network just a plain old wpa2 network, or is it some kind of fancy enterprise type setup?

Edit: Oh, and what you did there with the sysctl.d thing simply stops the system from trying to get an IPv6 connection. What happens if you entirely disable it with the kernel command line argument 'ipv6.disable=1'?

Last edited by WonderWoofy (2014-01-15 18:19:52)

eduardowoj · 2014-01-15 18:23:25

The network here is a simple WPA2 with PEAP authentication. I tried dhcpcd, but with no avail.

I didn't tried to connect manually this way. Forgive me, but, how do I do this?

WonderWoofy · 2014-01-15 18:28:41

See the wiki page on wireless networking. It should have instructions there.

Trilby · 2014-01-15 18:32:27

eduardowoj wrote:

I tried
ip link set wlan0 up
, but I couldn't bring the state to UP, it stayed on DOWN.

Your looking at the wrong part of the output. Your interface is UP (the part within the angled brackets). The DOWN later on that line indicates that you just don't have an active connection.

I'd second WW's suggestion to connect (for now) manually with wpa_supplicant. The 'how' is described here. When you don't know, always check the wiki.

eduardowoj · 2014-01-15 18:45:52

I read the wiki and tried the process, but it seems I don't have iw installed:

$ iw dev wlan0 link
iw: command not found

But dhcpcd works. However, first running as a regular user

$ dhcpcd wlan0: interface wlan0 not found

(I don't remember if this is the exact output, because I need to keep rebooting to and from Windows to test the commands).

When I try as sudo:

$ dhcpcd wlan0: waiting for carrier
dhcpcd wlan0: timed out
dhcpcd wlan0: exited

Trilby · 2014-01-15 18:56:33

iw is not required, but if you want it install it with `pacman -S iw`:

$ pkgfile iw
core/iw

The important step is wpa_supplicant, and (most likely) wpa_passphrase, for example:

wpa_passprhase THE_NETWORK_NAME THE_PASSPHRASE > my.conf
wpa_supplicant -B -i wlan0 -c my.conf
dhcpcd wlan0

eduardowoj · 2014-01-16 12:03:58

Thank you all for the help, but this last tip didn't worked either.

Yesterday, when I came home, the wifi worked like a charm. I decided to give up, and go back to Fedora, because I can't depend on a random wifi like this. I installed it in a usb stick and booted it live just to check something. And I discovered something that changed my mind:

I can't connect to the university's wifi on Fedora too! So the bug is in the new KDE network manager, which is a huge piece of rubbish compared to the previous version. I'll ask for help in the KDE forums, because this bug may be affecting other users too. When I find the solution with the KDE guys, I'll post it here and mark the thread as closed, to help other people too.

Thanks!

Trilby · 2014-01-16 12:42:35

eduardowoj, these forums rarely work by someone giving a suggestion that magically solves a problem. They work by a process of troubleshooting. If you're going to give up, so be it; but the process would continue by reporting which step failed, then we could dig deeper into that step to precisely identify the problem. Right now we don't have a precisely defined problem, only a 'something doesn't work'.

wpa_supplicant does not depend on kde network manager, so the problem isn't limited to kde's network manager. I suspect the first thing the KDE people will ask is whether you can connect manually. When you say no, they'll conclude that it is not a KDE problem, but a more basic issue with your set up.

eduardowoj · 2014-01-16 12:50:14

Trilby wrote:

wpa_supplicant does not depend on kde network manager, so the problem isn't limited to kde's network manager. I suspect the first thing the KDE people will ask is whether you can connect manually. When you say no, they'll conclude that it is not a KDE problem, but a more basic issue with your set up.

Sorry, I imagined that those two things were close. I think this is weird, because I can't connect in both systems, both are KDE with the same nm. I imagined the problem was in KDE, not in arch... Again, sorry for that, since I get this problem in other distros too I'll not give up!

I think that if I describe the two wifi networks we have here, it may help to track the problem. One of the networks is open, without any authentication in the configuration. Anyone can connect, but the authentication of the users occurs in browser. The other is a WPA2 with PEAP authentication, which needs the username and password to be entered in the configurations of the connection.

I tried the wpa_supplicant commands, but they didn't worked. I think this is due to the type of authentication the network requires.

I was suspecting of with my drivers or my kernel, but since I could connect at home, I discarded this option.

Update: I dug deeper searching for more information. I got some output that may tell something:

$ NetworkManager --no-daemon --log-level=INFO

(lots of descriptions of other connections)

<info> WiFi hardware radio set enabled
<error> [1389878476.806644] [nm-dbus-manager.c:338] nm_dbus_manager_start_service(): Could not acquire the NetworkManager service as it is already taken.
<error> [1389878476.806686] [main.c:592] main(): failed to start the dbus service.
<info> exiting (error)

Update 2: I managed to get a working cable connection, downgraded kernel to 3.11 (because I read somewhere that some people were experiencing problems with iwlwifi and the kernel 3.12) but it didn't worked yet. I then reupdated my system, installed and configured wicd, in which, when I try to connect to some wireless, it stays a long time displaying the message "Obtaining and IP address" and fails. Maybe it is some issue with dhcp?

Last edited by eduardowoj (2014-01-16 17:49:10)

patelvrajn · 2014-01-18 05:16:28

Does your network card support all connections meaning 802.11a/b/g/n? If not you might need to connect to another network. If it failed to obtain an IP address, it would connect to the network but without internet but not completely disconnect. Have you installed the proprietary driver for your wireless card (if it requires one)?

eduardowoj · 2014-01-18 10:45:08

Yes, it supports. It worked normally when I was using Fedora 18, 10 day ago. I didn't needed to install any proprietary drivers, because I can connect in some networks. For example, now I'm using the internet in Arch, in my laptop, at home.

I do think there is a problem with the access point I was trying to connect. Three different distros couldn't connect to the network, and I had some difficulties connecting to them in Windows too. However, I'm going to travel tomorrow and it'll be a week without internet to post here.

Thank you all for your help!

eduardowoj · 2014-01-27 10:50:36

Hello guys,

I came back from my travel, and today I could connect at my university, in a different place. I think, by the symptoms I described, it was just an issue with the access point. I'm marking this thread as solved.

Sorry for bothering you all :-(

Arch Linux

#1 2014-01-15 16:16:37

[Solved] Some wifi networks connects, some don't

#2 2014-01-15 16:41:22

Re: [Solved] Some wifi networks connects, some don't

#3 2014-01-15 17:09:10

Re: [Solved] Some wifi networks connects, some don't

#4 2014-01-15 17:49:51

Re: [Solved] Some wifi networks connects, some don't

#5 2014-01-15 18:10:11

Re: [Solved] Some wifi networks connects, some don't

#6 2014-01-15 18:18:02

Re: [Solved] Some wifi networks connects, some don't

#7 2014-01-15 18:23:25

Re: [Solved] Some wifi networks connects, some don't

#8 2014-01-15 18:28:41

Re: [Solved] Some wifi networks connects, some don't

#9 2014-01-15 18:32:27

Re: [Solved] Some wifi networks connects, some don't

#10 2014-01-15 18:45:52

Re: [Solved] Some wifi networks connects, some don't

#11 2014-01-15 18:56:33

Re: [Solved] Some wifi networks connects, some don't

#12 2014-01-16 12:03:58

Re: [Solved] Some wifi networks connects, some don't

#13 2014-01-16 12:42:35

Re: [Solved] Some wifi networks connects, some don't

#14 2014-01-16 12:50:14

Re: [Solved] Some wifi networks connects, some don't

#15 2014-01-18 05:16:28

Re: [Solved] Some wifi networks connects, some don't

#16 2014-01-18 10:45:08

Re: [Solved] Some wifi networks connects, some don't

#17 2014-01-27 10:50:36

Re: [Solved] Some wifi networks connects, some don't

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