Wifi problem: All devices connect but my arch installation doesn't

phonky · 2015-03-11 15:56:05

I recently moved to a new house. In the former apartment, the same arch linux desktop box I am using now has been working just fine with wifi.

When I moved in here, all my devices (an Android phone and a laptop running manjaro) connected with the wifi router and I have internet on them. Connection establishment was a bit slow but successful.
On my arch linux desktop box though I can't get the connection to work. The same box, when booting with elementaryOS (I have dual boot configuration), with the same wifi USB dongle, connects fine.
What could be going wrong?

Arch linux actually DOES detect the interface. I can run

# iwconfig wlp0s22f2u4 essid MYESSID
# iwconfig
wlp0s22f2u4  IEEE 802.11bgn ESSID: "MYESSID"  
     Mode: Managed    Access Point: Not-Associated    Tx-Power=20 dBm
     Retry short limit:7     RTS thr=2347 B     Fragment thr: off
     Encryption key:off
     Power Management:off

But when I try to set the key:

# iwconfig wlp0s22f2u4 key "s:MYKEY"
Error for wireless request "Set Encode"  (8B2A) :
   SET failed on device wlp0s22f2u4 ; Invalid argument

I've tried different approaches (wpa_supplicant, NetworkManager, etc), and it seems I get stuck when trying to get the IP, issuing

# dhcpcd -d4 2lp0s22f2u4 
...
wlp0s22f2u4: waiting for carrier
timed out
exited

Again, strange as the same box with elementaryOS can connect and other devices connect as well.

#lsusb:
Bus 004 Deice 003: ID 0bda:8178 Realtek Semcionductor Corp. RTL8192CU 802.11n WLAN Adapater

Last edited by phonky (2015-03-11 16:06:43)

Head_on_a_Stick · 2015-03-11 19:48:24

phonky wrote:

I've tried different approaches (wpa_supplicant, NetworkManager, etc), and it seems I get stuck when trying to get the IP, issuing

Have you tried assigning static IPs?
https://wiki.archlinux.org/index.php/Wi … IP_address
https://wiki.archlinux.org/index.php/Ne … IP_address

ewaller · 2015-03-11 20:13:56

Trying to run dhcpcd before being associated with the access point is fruitless.
Can you do a site survey using the scan option of iw ? Do you see your access point?
Is this access point using WPA? Or is it really still using WEP?

phonky · 2015-03-11 20:18:16

Thanks @Head_on_a_Stick for chiming in.

Yes I have tried and I can assign the IP without problems, and added the default route. But no joy.
I have the other laptop running at 192.168.1.66, assigned the failing desktop box to 192.168.1.62/24.
While from the laptop I can ping 192.168.1.254, which appears to be the router, I can't from the desktop box. The latter even can't ping the laptop at .66...

When I run
wpa_supplicant -d -Dnl80211,wext -iwlp0s22f2u4 -c /etc/wpa_supplicant/wpa_supplicant.conf

I can see several positive output:

EAPOL: SUPP_PAE entering state AUTHENTICATING
EAPOL: SUPP_BE entering state SUCCESS
EAP: EAP entering DISABLED
EAPOL: SUPP_PAE entering state AUTHENTICATED
EAPOL: Supplicant port status: Authorized
nl80211: Set supplicant port authorized for $SSID-addr
EAPOL: SUPP_BE entering state IDLE
EAPOL: authentication completed - result=SUCCESS
EAPOL: startWhen --> 0
EAPOL: disable timer tick

which seems to suggest that authentication actually succeeded....
I use i3 as wm, and in the i3status bar I can see

W: (017% at SSID)  No IP

But as said statically assigning an IP also doesn't work...
Out of my ideas here...:(((

phonky · 2015-03-11 20:20:28

maybe the signal is too weak...(my laptop says normally between 40% and 60% and is just at the right same spot , but the desktop may be running a lower-end usb wifi-key which doesn't get the same efficiency....don't know)

phonky · 2015-03-11 20:26:58

@ewaller
iw dev wlp0s22f2u4 scan
can see my AP, and outputs some info

ewaller · 2015-03-12 00:13:58

Can you get iwconfig to report that you are associated with the access point? If not, higher level things like IP addresses are moot. Not being associated on wireless is like not having the cable plugged in on wired connections. You can force an IP address, but you still won't be able to talk.

phonky · 2015-03-12 01:10:47

gotcha @ewaller.

But how do I ..."get iwconfig to report that you are associated with the access point?"

Indeed I believe what you are saying is happening now, in that I am not really physically connected - but I need to check. How?

phonky · 2015-03-12 02:41:04

#iw dev wlp0s22f2u4 link
Connected to 58:23:8c:00:f3:54 (on wlp0s22f2u4)
       SSID: MYSSID
       freq: 2452
       RX: 61243 bytes (568 packets)
       TX: 472 bytes (5 packets)
       signal: -98dBm
       tx bitrate: 7.2 MBit/s MCS @ short GI

       bss flags:       short-slot-time
       dtim period:  1
       beacon int:    1000

Looks like I am connected to the AP....still it says no IP in the i3 status line....this is really weird....

Last edited by phonky (2015-03-12 02:41:19)

phonky · 2015-03-12 03:02:35

What's even more weird...I can access with the same machine and usb wifi device to my Android mobile hotspot...
Unfortunately I don't have access to the new house' AP in order to check the config....

ewaller · 2015-03-12 03:36:37

Yes, you are connected to the AP. Good.
And, while associated, dhcpcd times out ? .... ouch.

As a test, can I suggest you try dhclient as an alternative to dhcpcd. Sometimes, it works a bit better (if not quite as compliant with the specification)

What is the router make and model? Have you access to the router logs?

Arch Linux

#1 2015-03-11 15:56:05

Wifi problem: All devices connect but my arch installation doesn't

#2 2015-03-11 19:48:24

Re: Wifi problem: All devices connect but my arch installation doesn't

#3 2015-03-11 20:13:56

Re: Wifi problem: All devices connect but my arch installation doesn't

#4 2015-03-11 20:18:16

Re: Wifi problem: All devices connect but my arch installation doesn't

#5 2015-03-11 20:20:28

Re: Wifi problem: All devices connect but my arch installation doesn't

#6 2015-03-11 20:26:58

Re: Wifi problem: All devices connect but my arch installation doesn't

#7 2015-03-12 00:13:58

Re: Wifi problem: All devices connect but my arch installation doesn't

#8 2015-03-12 01:10:47

Re: Wifi problem: All devices connect but my arch installation doesn't

#9 2015-03-12 02:41:04

Re: Wifi problem: All devices connect but my arch installation doesn't

#10 2015-03-12 03:02:35

Re: Wifi problem: All devices connect but my arch installation doesn't

#11 2015-03-12 03:36:37

Re: Wifi problem: All devices connect but my arch installation doesn't

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