wlan0 vs DHCP

dapla · #1 20th November 2008, 07:18 PM

It seems that wlan0 is authenticating and associating with my AP, but can't get an internet address from DHCP. I wonder if this looks familiar to anyone?

When I use dhclient I get the following output.

Code:

[root@Congo ~]# dhclient -r -v wlan0
Internet Systems Consortium DHCP Client 4.0.0
Copyright 2004-2007 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

Listening on LPF/wlan0/00:16:b6:55:39:2d
Sending on   LPF/wlan0/00:16:b6:55:39:2d
Sending on   Socket/fallback
[root@Congo ~]# dhclient -v wlan0
Internet Systems Consortium DHCP Client 4.0.0
Copyright 2004-2007 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

Listening on LPF/wlan0/00:16:b6:55:39:2d
Sending on   LPF/wlan0/00:16:b6:55:39:2d
Sending on   Socket/fallback
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 3
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 6
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 6
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 14
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 14
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 11
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 7
No DHCPOFFERS received.
No working leases in persistent database - sleeping.

dmesg gives me the following info:

Code:

[root@Congo ~]# dmesg | grep wlan0
ADDRCONF(NETDEV_UP): wlan0: link is not ready
wlan0: authenticate with AP 00:1e:e5:74:26:c6
wlan0: authenticated
wlan0: associate with AP 00:1e:e5:74:26:c6
wlan0: RX AssocResp from 00:1e:e5:74:26:c6 (capab=0x11 status=0 aid=1)
wlan0: associated
ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
wlan0: no IPv6 routers present
ADDRCONF(NETDEV_UP): wlan0: link is not ready
wlan0: authenticate with AP 00:1e:e5:74:26:c6
wlan0: authenticated
wlan0: associate with AP 00:1e:e5:74:26:c6
wlan0: RX AssocResp from 00:1e:e5:74:26:c6 (capab=0x11 status=0 aid=1)
wlan0: associated
ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
wlan0: no IPv6 routers present
wlan0: authenticate with AP 00:1e:e5:74:26:c6
wlan0: authenticated
wlan0: associate with AP 00:1e:e5:74:26:c6
wlan0: RX ReassocResp from 00:1e:e5:74:26:c6 (capab=0x11 status=0 aid=1)
wlan0: associated

iwconfig and ifconfig look good.

Code:

[root@Congo ~]# iwconfig wlan0
wlan0     IEEE 802.11bg  ESSID:"howdyNeighbors"  
          Mode:Managed  Frequency:2.437 GHz  Access Point: 00:1E:E5:74:26:C6   
          Bit Rate=1 Mb/s   Tx-Power=21 dBm   
          Retry min limit:7   RTS thr:off   Fragment thr=2352 B   
          Encryption key:<deleted>   Security mode:open
          Power Management:off
          Link Quality=73/100  Signal level:-40 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

[root@Congo ~]# ifconfig wlan0
wlan0     Link encap:Ethernet  HWaddr 00:16:B6:55:39:2D  
          inet6 addr: fe80::216:b6ff:fe55:392d/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1286 errors:0 dropped:0 overruns:0 frame:0
          TX packets:37 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:353605 (345.3 KiB)  TX bytes:10152 (9.9 KiB)

BTW:

Code:

[root@Congo ~]# uname -a
Linux Congo 2.6.27.5-41.fc9.x86_64 #1 SMP Thu Nov 13 20:29:07 EST 2008 x86_64 x86_64 x86_64 GNU/Linux

nspmangalore · #2 21st November 2008, 03:27 PM

it seems to fail finding DHCP servers. are you connected to a DHCP server?

scottro · #3 21st November 2008, 11:42 PM

I've had this happen too--sometimes, in F10 with the AR5007EG card. Recent kernel updates (I've been using the 2.6.27 kernel's builtin ath5k driver) seem to have fixed it for me. This is running from shell, no network manager, just doing a wpa_supplicant, and then, once it's authenticated, running dhclient on the card.

I've also seen this happen in SimplyMepis 8 beta and Mandriva 2009, in both cases with a KDE desktop. (I thought it might be the KDE network manager stuff causing the trouble, but others have no problem, so probably not.)

In most cases when it happened to me on FedI have, on some Linux lists, been known to suggest to some people posting their problems, that since Linux is case sensitive and many commands have to be typed in, that the first step they must make is to get a keyboard with a working shift, period and vowel keys.

ora, it would go away after a reboot. Very annoying though. Another symptom would be that it seemed to be sucking processor time, everything else would become very slow--for example, I'd type and it would literally take 3 seconds or more for it to be echoed to the screen.

If that is an Atheros card and you're using the 2.6. 27 kernel on F10 (in which case, you should mention it and I'll move it into the F10 section--regardless, it is often very helpful to know the make of the wireless card), it might work if you change from the ath5k driver to the MadWifi drivers. This has worked for some.

However, before speculating further, I'd like more information on card and kernel, so I don't waste your time.

dapla · #4 24th November 2008, 02:22 PM

[root@Congo ~]# lspci | grep RaLink
04:07.0 Network controller: RaLink RT2500 802.11g Cardbus/mini-PCI (rev 01)
[root@Congo ~]# uname -a
Linux Congo 2.6.27.5-41.fc9.x86_64 #1 SMP Thu Nov 13 20:29:07 EST 2008 x86_64 x86_64 x86_64 GNU/Linux

dapla · #5 24th November 2008, 02:25 PM

Quote:

Originally Posted by nspmangalore

it seems to fail finding DHCP servers. are you connected to a DHCP server?

My AP "howdyNeighbors" is my wireless router. I am authenticated and associated with it. It gives DHCP to other computers on my network. I don't know why it won't serve my linux workstation.

scottro · #6 24th November 2008, 03:52 PM

Wow, how did I miss the fact that you'd already given all the info I requested? Sigh, old age and apologies.

More and more, I'm beginning to wonder if something is wrong with 2.6.27's dhclient. It's just that somehow, it doesn't seem to work as well as it used to. As I said, I often get those errors with Fedora for no reason that I can determine. Then, it goes away and works. I can't file a bug report, because it would be something like, Gee, dhclient doesn't work as well in F10.

Just to make sure it isn't the card (though I don't see it being the card as it's getting the SSID) would you please try
iwlist wlan0 scan

It should come up with various access points.

Also, it looks like you're not using NetworkManager, right? Is it definitely turned off? It will sometimes warp dhclient to its own nefarious purposes if left running.

dapla · #7 24th November 2008, 04:13 PM

Yes, I am not using NetworkManger. I disabled the service.

Code:

[root@Congo ~]# iwlist wlan0 scan
wlan0     Scan completed :
          Cell 01 - Address: 00:1E:E5:74:26:C6
                    ESSID:"howdyNeighbors"
                    Mode:Master
                    Channel:6
                    Frequency:2.437 GHz (Channel 6)
                    Quality=53/100  Signal level:-42 dBm  
                    Encryption key:on
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s
                              24 Mb/s; 36 Mb/s; 54 Mb/s; 6 Mb/s; 9 Mb/s
                              12 Mb/s; 48 Mb/s
                    Extra:tsf=0000008750181183
                    Extra: Last beacon: 7ms ago
          Cell 02 - Address: 00:18:F8:1B:2A:3D
                    ESSID:"larkin"
                    Mode:Master
                    Channel:11
                    Frequency:2.462 GHz (Channel 11)
                    Quality=49/100  Signal level:-63 dBm  
                    Encryption key:on
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s
                              24 Mb/s; 36 Mb/s; 54 Mb/s; 6 Mb/s; 9 Mb/s
                              12 Mb/s; 48 Mb/s
                    Extra:tsf=000002a0e566c18e
                    Extra: Last beacon: 41ms ago
          Cell 03 - Address: 00:1B:2F:63:9A:CC
                    ESSID:"amylen"
                    Mode:Master
                    Channel:11
                    Frequency:2.462 GHz (Channel 11)
                    Quality=47/100  Signal level:-75 dBm  
                    Encryption key:on
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
                              12 Mb/s; 24 Mb/s; 36 Mb/s; 9 Mb/s; 18 Mb/s
                              48 Mb/s; 54 Mb/s
                    Extra:tsf=000001e4bd72173f
                    Extra: Last beacon: 40ms ago

scottro · #8 24th November 2008, 04:27 PM

Ok, so much for the possible easy quick fixes.
Would you mind trying the following? For some odd reason, I've sometimes found this to work when doing it the normal way wouldn't. No guarantee that it will work in your case, but should only take a few minutes.
As I said, sometimes, doing it this way has sometimes worked for me, but I have no intelligent explanation, and it may be a complete waste of your time.

Assuming you use wpa_supplicant to authenticate, first, in /etc/sysconfig/network-scripts/ifcfg-wlan0 set it to not come up on boot--it probably has ONBOOT=yes in there, change it to no.

Turn off wpa_supplicant in services.

chkconfig wpa_supplicant off

Reboot.
Now, run it from command line, where it should, judging from what you're seeing, authenticate.

wpa_supplicant -Dwext -iwlan0 -c/etc/wpa_supplicant/wpa_supplicant.conf

Then, after it connects to your WPA, in another terminal (since wpa_supplicant will be keepng the terminal you used for the command

dhclient -v wlan0

See if you have any luck. Note that this is a stab in the dark, and if you don't have time to play with it, I understand and won't feel slighted.

dapla · #9 24th November 2008, 05:22 PM

Interesting. I tried what you suggested. I should note that I am using WEP.

Code:

[root@Congo ~]# wpa_supplicant -Dwext -iwlan0 -c/etc/wpa_supplicant/wpa_supplicant.conf 
CTRL-EVENT-SCAN-RESULTS 
CTRL-EVENT-SCAN-RESULTS 
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
ioctl[SIOCSIWENCODEEXT]: No such file or directory
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
ioctl[SIOCSIWENCODEEXT]: No such file or directory
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
ioctl[SIOCSIWENCODEEXT]: No such file or directory
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
ioctl[SIOCSIWENCODEEXT]: No such file or directory
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
ioctl[SIOCSIWENCODEEXT]: No such file or directory
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
ioctl[SIOCSIWENCODEEXT]: No such file or directory
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
ioctl[SIOCSIWENCODEEXT]: No such file or directory

The contents of /etc/wpa_supplicant/wpa_supplicant.conf :

Code:

[root@Congo ~]# cat /etc/wpa_supplicant/wpa_supplicant.conf 
ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=wheel

[root@Congo ~]#

Also:

Code:

[root@Congo ~]# dhclient -v wlan0
Internet Systems Consortium DHCP Client 4.0.0
Copyright 2004-2007 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

Listening on LPF/wlan0/00:16:b6:55:39:2d
Sending on   LPF/wlan0/00:16:b6:55:39:2d
Sending on   Socket/fallback
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 3
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 5
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 11
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 20
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 7
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 7
No DHCPOFFERS received.
No working leases in persistent database - sleeping.
[root@Congo ~]#

scottro · #10 24th November 2008, 05:57 PM

Ah, well wpa_conf wouldn't work in its default configuration, sorry. I'd assumed you were running wpa rather than WEP, or using wpa_conf to do WEP, though of course, I had no reason to believe either.

dapla · #11 24th November 2008, 06:49 PM

Yes, I tried to switch WPA, but can't get my ancient powerbook running OSX to switch. I'm not sure what this has to do with anything though. dmesg shows that I am authenticated and associated with the AP.

scottro · #12 24th November 2008, 07:14 PM

Sorry, I wasn't clear, I'm afraid. It doesn't have much to do with anything, simply that running wpa_supplicant from the command line wouldn't work as I had written it because there is no special configuration in there.

Do you have another distro with a live CD for the powerbook? I wonder if it's a Fedora thing, or not. That is, if for example, an Ubuntu for powerbook got an address through DHCP without problem, then one could guess that it is definitely a Fedora problem.

Frankly, I'm a bit stumped. As I said, I had it happen once in awhile, but it always fixed itself with an reboot and recent updates seem to have ended the problem that I was having.