Wireless fails to get IP from DHCP?

Hi all,

I’m having a really strange problem with my laptop at the moment that some of you might be able to help with. I have five computers with OpenSUSE installed and I’m fairly good at figuring out problems but this one has me stumped. All the other computers are working fine with mostly wireless connections but one laptop continues to have trouble getting a connection, although it does works sometimes so it’s intermittent.

The laptop is a Dell Latitude D620 with OpenSUSE 11.0 installed. It has the following information about the wireless card:

PRO/Wireless 3945ABG Network Connection (Not connected)
MAC : 00:18:de:94:ea:e5
Device Name: wlan0
Started automatically at boot
IP address assigned using DHCP

And the hardware module is iwl3945.

The output of ifconfig is this:

eth0 Link encap:Ethernet HWaddr 00:15:C5:57:CF:69
inet addr:192.168.1.7 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::215:c5ff:fe57:cf69/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:3950 errors:0 dropped:0 overruns:0 frame:0
TX packets:3115 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:4319889 (4.1 Mb) TX bytes:435948 (425.7 Kb)
Interrupt:18

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:354 errors:0 dropped:0 overruns:0 frame:0
TX packets:354 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:27316 (26.6 Kb) TX bytes:27316 (26.6 Kb)

wlan0 Link encap:Ethernet HWaddr 00:18:DE:94:EA:E5
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:10 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:2036 (1.9 Kb)

wmaster0 Link encap:UNSPEC HWaddr 00-18-DE-94-EA-E5-00-00-00-00-00-00-00-00-00-00
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

The output of iwconfig is this:

lo no wireless extensions.

eth0 no wireless extensions.

wmaster0 no wireless extensions.

wlan0 IEEE 802.11g ESSID:“BurmaniaWLAN”
Mode:Managed Frequency:2.457 GHz Access Point: 00:1B:2F:BD:04:3B
Bit Rate=54 Mb/s Tx-Power=27 dBm
Retry min limit:7 RTS thr:off Fragment thr=2352 B
Encryption key:off
Link Quality=98/100 Signal level=-27 dBm Noise level=-127 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

Now, everything seems to be okay except that the wlan0 doesn’t have an IP address. If I use KNetworkManager the wireless network is shown with an extremely strong signal but when I select it the little cog turns and turns and the progress bar never gets about halfway across before I get the little grey world icon indicating that there is no connection.

If I use dhcpcd on wlan0 it just sits there and fails after a minute or so.

I don’t understand why I have a connection but often fail to get a IP address. It’s even more puzzling that it’s intermittent?! I can’t seem to find a way to see a decent log file to give me an idea of what is going wrong.

Can anyone help or point me in the right direction?

Cheers,
Richard.

your IP address on the LAN (even if you use DHCP) is set in the router. Usually you will have a range within the confines of your needs.
eg:
router would be 192.168.0.1

you would then say ‘I need 5 computers to be able to connect’ wireless or otherwise.

so you set a range
starting: 192.168.0.2
end: 192.168.0.6

Now I always assign each connecting PC a specific IP with access control by MAC
and then wireless encryption

But you would still use DHCP in the settings in Yast and knetworkmanager

N.B.
I think you can also set the MAC address for the router in Yast settings for the network, but I don’t think that is necessary.

maybe you can check this link:
http://www.linuxhomenetworking.com/wiki/index.ph
I’m learning a lot from it so it might help you.