'/sbin/dhclient wlan0' not working in CentOS 5.3

saivin · 08-03-2009, 10:32 AM

Hi,
I'm having trouble with my wireless setup in CentOS 5.3. The wireless card is Intel 3945ABG. I've installed iwl3945-firmware and loaded the module also. But I'm not able to get IP address from DHCP. When I do /sbin/dhclient wlan0 I get the following error:

Code:

[saivin@sv-centos ~]$ sudo /sbin/dhclient wlan0
Password:
Internet Systems Consortium DHCP Client V3.0.5-RedHat
Copyright 2004-2006 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

wmaster0: unknown hardware address type 801
wmaster0: unknown hardware address type 801
Listening on LPF/wlan0/00:1c:bf:c8:f2:1b
Sending on   LPF/wlan0/00:1c:bf:c8:f2:1b
Sending on   Socket/fallback
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 18
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 16
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 19
No DHCPOFFERS received.
No working leases in persistent database - sleeping.

However, dhclient works fine for eth0. Wireless is associated with my AP too.

Code:

[root@sv-centos saivin]# /sbin/iwconfig wlan0
Warning: Driver for device wlan0 recommend version 21 of Wireless Extension,
but has been compiled with version 20, therefore some driver features
may not be available...

wlan0     IEEE 802.11  ESSID:"SV"
          Mode:Managed  Frequency:2.412 GHz  Access Point: Not-Associated
          Tx-Power=15 dBm
          Retry min limit:7   RTS thr:off   Fragment thr=2352 B
          Encryption key:off
          Link Quality:0  Signal level:0  Noise level:0
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

It also scans my AP fine.

Code:

[root@sv-centos saivin]# /sbin/iwlist wlan0 scan
Warning: Driver for device wlan0 recommend version 21 of Wireless Extension,
but has been compiled with version 20, therefore some driver features
may not be available...

wlan0     Scan completed :
          Cell 01 - Address: 00:1B:57:FD:4D:19
                    ESSID:"SV"
                    Mode:Master
                    Channel:11
                    Frequency:2.462 GHz (Channel 11)
                    Quality=93/100  Signal level=-36 dBm  Noise level=-127 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=00000000190c8185

The only problem is that it is not getting IP from DHCP. Giving an IP manually with '/sbin/ifconfig wlan0 192.168.1.4' does not help either. Coz, it does not ping my router.

It is giving a warning. I can not make out what it means. Is my problem related to this?

michaelk · 08-03-2009, 05:45 PM

Are you using wireless encryption? I would guess you have not setup any encryption keys yet and you will not be able to receive an IP address until this is accomplished.

saivin · 08-04-2009, 03:19 AM

I have enabled WEP encryption on router (it doesnot support WPA or higher). Do I have to disable it? Or edit something on the system? (Encrypted wireless works fine on Ubuntu)

michaelk · 08-04-2009, 07:13 AM

No, you just need to configure your wireless to use WEP. network manager or wicd are GUI wireless configuration tools but you can manually add the WEP key with iwconfig or you can use a the network script too.

Here are a couple of wireless network script examples that use wep keys.
http://www.linuxquestions.org/questi...ntos-5-547162/
http://gno3dtet.eseb.net/centos5.php?x=3&

saivin · 08-05-2009, 12:28 PM

I have tried using wep key with iwconfig and network manager (will give a try to those scripts too). But my problem is that I'm not getting IP address. I tried to give manual ip and them tried to ping my router. No luck.

Btw, could you make out something from the 'Warning:' given in my #1 post? I don't know what to do for it. Is my problem related to that warning?

michaelk · 08-06-2009, 06:34 AM

Unless your associated with the router you will be unable to get an IP address. Difficult to tell if the warning is associated with your problems. You might try turning encryption off and see if it works.

saivin · 08-08-2009, 02:33 AM

Hi michaelk,
Here is the update:
I tried with encryption on and off, WEP open/shared etc nothing worked. Then I followed the wiki on CentOS related to WPASupplicant

And now, when I try to associate with wpa_supplicant I get the following error:

Code:

[root@sv-centos saivin]# /usr/sbin/wpa_supplicant -i wlan0 -D wext -c /etc/wpa_supplicant/wpa_supplicant.conf
Device wlan0 kernel driver name: iwl3945.
ioctl[SIOCSIWAUTH]: Operation not supported
WEXT auth param 4 value 0x0 - Trying to associate with 00:1b:57:fd:4d:19 (SSID='SV' freq=2462 MHz)
Associated with 00:1b:57:fd:4d:19
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
ioctl[SIOCSIWENCODEEXT]: No such file or directory
Authentication with 00:00:00:00:00:00 timed out.
Trying to associate with 00:1b:57:fd:4d:19 (SSID='SV' freq=2462 MHz)
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
ioctl[SIOCSIWENCODEEXT]: No such file or directory
Associated with 00:1b:57:fd:4d:19
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
ioctl[SIOCSIWENCODEEXT]: No such file or directory
Authentication with 00:00:00:00:00:00 timed out.
Trying to associate with 00:1b:57:fd:4d:19 (SSID='SV' freq=2462 MHz)
Associated with 00:1b:57:fd:4d:19
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
ioctl[SIOCSIWENCODEEXT]: No such file or directory
Trying to associate with 00:1b:57:fd:4d:19 (SSID='SV' freq=2462 MHz)
Associated with 00:1b:57:fd:4d:19
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys
ioctl[SIOCSIWENCODEEXT]: No such file or directory

[1]+  Stopped                 /usr/sbin/wpa_supplicant -i wlan0 -D wext -c /etc/wpa_supplicant/wpa_supplicant.conf

Here is the dmesg output:

Code:

ADDRCONF(NETDEV_UP): wlan0: link is not ready
[drm] Initialized drm 1.0.1 20051102
ACPI: PCI Interrupt 0000:00:02.0[A] -> GSI 16 (level, low) -> IRQ 169
[drm] Initialized i915 1.8.0 20060929 on minor 0
wlan0: Initial auth_alg=0
wlan0: authenticate with AP 00:1b:57:fd:4d:19
wlan0: RX authentication from 00:1b:57:fd:4d:19 (alg=0 transaction=2 status=0)
wlan0: authenticated
wlan0: associate with AP 00:1b:57:fd:4d:19
wlan0: RX AssocResp from 00:1b:57:fd:4d:19 (capab=0x411 status=0 aid=1)
wlan0: associated
wlan0: switched to short barker preamble (BSSID=00:1b:57:fd:4d:19)
wlan0: disassociate(reason=3)
wlan0: Initial auth_alg=0
wlan0: authenticate with AP 00:1b:57:fd:4d:19
wlan0: RX disassociation from 00:1b:57:fd:4d:19 (reason=7)
wlan0: RX authentication from 00:1b:57:fd:4d:19 (alg=0 transaction=2 status=0)
wlan0: authenticated
wlan0: associate with AP 00:1b:57:fd:4d:19
wlan0: RX AssocResp from 00:1b:57:fd:4d:19 (capab=0x411 status=0 aid=1)
wlan0: associated
wlan0: switched to short barker preamble (BSSID=00:1b:57:fd:4d:19)
wlan0: disassociate(reason=3)
wlan0: Initial auth_alg=0
wlan0: authenticate with AP 00:1b:57:fd:4d:19
wlan0: RX authentication from 00:1b:57:fd:4d:19 (alg=0 transaction=2 status=0)
wlan0: authenticated
wlan0: associate with AP 00:1b:57:fd:4d:19
wlan0: RX AssocResp from 00:1b:57:fd:4d:19 (capab=0x411 status=0 aid=1)
wlan0: associated
wlan0: switched to short barker preamble (BSSID=00:1b:57:fd:4d:19)
ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
wlan0: disassociate(reason=3)
wlan0: Initial auth_alg=0
wlan0: authenticate with AP 00:1b:57:fd:4d:19
wlan0: RX authentication from 00:1b:57:fd:4d:19 (alg=0 transaction=2 status=0)
wlan0: authenticated
wlan0: associate with AP 00:1b:57:fd:4d:19
wlan0: RX AssocResp from 00:1b:57:fd:4d:19 (capab=0x411 status=0 aid=1)
wlan0: associated
wlan0: switched to short barker preamble (BSSID=00:1b:57:fd:4d:19)
wlan0: disassociate(reason=3)
wlan0: no IPv6 routers present

Any clues?