WiFi connected to AP but fails to obtain IP Address

Oh yeah, in all cases, the networks are supposed to be DHCP, and that is how they are configured in Networking and WifiRadar. I even tried the command line to release and re-obtain IP with no luck.

I have the same card and same machine, and I have this working, so I think I can help.

You need to use eth1. Did you try the following yet?

bash> sudo ifdown eth1
bash> sudo ifup eth1

This will basically just restart the wireless interface.

Also, I use NetworkManager instead of WifiRadar, and it works beautifully. Try 'apt-get install network-manager-gnome' and relogin.

Still no luck. I paste what I get from those commands below. Bottom line is this message:
No DHCPOFFERS received.
No working leases in persistent database - sleeping.

Netmanager in the notifications panel only showed a single radio-button for the wired network. How do I access the UI to tell it what the wireless config is (I have 3 locations with 3 different wireless networks to regularly connect to)? Btw, let me stress that something must be connected to the wireless card in some way b/c I do see signals for various network ssids coming in. I just can't seem to get an IP address.

Here is the results:

root@laptop:/# ifdown eth1
There is already a pid file /var/run/dhclient.eth1.pid with pid 134993416
Internet Systems Consortium DHCP Client V3.0.4
Copyright 2004-2006 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

wifi0: unknown hardware address type 801
wifi0: unknown hardware address type 801
Listening on LPF/eth1/00:02:8a:9f:2a:7d
Sending on LPF/eth1/00:02:8a:9f:2a:7d
Sending on Socket/fallback

root@laptop:/# ifup eth1
There is already a pid file /var/run/dhclient.eth1.pid with pid 134993416
Internet Systems Consortium DHCP Client V3.0.4
Copyright 2004-2006 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

wifi0: unknown hardware address type 801
wifi0: unknown hardware address type 801
Listening on LPF/eth1/00:02:8a:9f:2a:7d
Sending on LPF/eth1/00:02:8a:9f:2a:7d
Sending on Socket/fallback
DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 6
DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 10
DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 16
DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 10
DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 11
No DHCPOFFERS received.
No working leases in persistent database - sleeping.
root@laptop:/#

Thanks again,

Can you paste the output of the following two commands please?

ifconfig

iwlist <device> scan

Where <device> is whatever the wireless device name is reported as in ifconfig (eth1, wifi0 etc).

Here you go. Note, in my office, I have no wired connection (so I have to re-boot into WinXP to get to the internet!) and the local [MyBusiness] Access Point does not transmit the SSID so I have to set up a config in Networking to find it in the first place. It is secured with 40-bit WEP, but I have also entered in the pw.

As you will see, there are often other signals available to me, and WiFi-radar (and in WinXP) I can see the SSID names and whether they are encrypted or not, but in the posted results, it is not apparant which is which (other than [MyBusiness]).

root@laptop:/# ifconfig
eth0 Link encap:Ethernet HWaddr 00:09:6B:53:FD:50
          UP BROADCAST 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)

eth1 Link encap:Ethernet HWaddr 00:02:8A:9F:2A:7D
          inet6 addr: fe80::202:8aff:fe9f:2a7d/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:1784 errors:2708838 dropped:0 overruns:2697022 frame:11816
          TX packets:996 errors:915 dropped:0 overruns:0 carrier:0
          collisions:10 txqueuelen:1000
          RX bytes:95218 (92.9 KiB) TX bytes:327096 (319.4 KiB)
          Interrupt:11 Base address:0x8000

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:154 errors:0 dropped:0 overruns:0 frame:0
          TX packets:154 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:17000 (16.6 KiB) TX bytes:17000 (16.6 KiB)

root@laptop:/# iwlist eth1 scan
eth1 Scan completed :
          Cell 01 - Address: 00:16:B6:F7:2A:CC
                    ESSID:""
                    Mode:Master
                    Frequency:2.437 GHz (Channel 6)
                    Quality=21/100 Signal level=-85 dBm Noise level:-94 dBm
                    Encryption key:on
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s
          Cell 02 - Address: 00:16:B6:F7:2D:93
                    ESSID:""
                    Mode:Master
                    Frequency:2.462 GHz (Channel 11)
                    Quality=23/100 Signal level=-84 dBm Noise level:-94 dBm
                    Encryption key:on
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s
          Cell 03 - Address: 00:16:B6:F7:2B:EC
                    ESSID:""
                    Mode:Master
                    Frequency:2.412 GHz (Channel 1)
                    Quality=19/100 Signal level=-86 dBm Noise level:-94 dBm
                    Encryption key:on
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s
          Cell 04 - Address: 00:13:19:31:82:00
                    ESSID:"MyBusiness"
                    Mode:Master
                    Frequency:2.427 GHz (Channel 4)
                    Quality=56/100 Signal level=-67 dBm Noise level:-94 dBm
                    Encryption key:on
                    Bit Rates:11 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s
                              48 Mb/s; 54 Mb/s

root@laptop:/# iwlist eth1 scan
eth1 Scan completed :
          Cell 01 - Address: 00:16:B6:F7:2D:93
                    ESSID:""
                    Mode:Master
                    Frequency:2.462 GHz (Channel 11)
                    Quality=19/100 Signal level=-86 dBm Noise level:-94 dBm
                    Encryption key:on
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s
          Cell 02 - Address: 00:13:19:31:82:00
                    ESSID:"MyBusiness"
                    Mode:Master
                    Frequency:2.427 GHz (Channel 4)
                    Quality=54/100 Signal level=-68 dBm Noise level:-94 dBm
                    Encryption key:on
                    Bit Rates:11 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s
                              48 Mb/s; 54 Mb/s

Thanks,

Still wondering . . .
Where does Linux keep network config info? Is it possible to delete or erase all wireless and network config info and have the OS auto-scan and re-configure network componants from scratch using the defaults?
What seems strange to me is that even if I disable the eth1 device in Networking, WiFi-radar still shows various networks available -- including my work AP (even though the ssid is not broadcast). So, it seems that WiFi-radar overides the Networking settings or works at a lower level. Perhaps I can delete all networking apps and protocols and re-install? I just don't know enough about Linux to solve this.
Btw, I should have mentioned that I had wireless networking running successfully under the Dapper version of Ubuntu for a little while until I did something strange (I think I deleted all the DNS, search and host info somehow).
Thanks for your help . . .

Well, there's a natty tool called Network Manager that can do a lot of the management of wireless for you. I use it on my laptops and it makes accessing wireless networks a lot less hassle:-

https://help.ubuntu.com/community/WifiDocs/NetworkManager

I stumbled upon this post since (obviously) I have the same problem. I have been playing around with Ubuntu for a while now. I just recently "upgraded" 2 laptops at home from W* to Edgy, to give them to my kids. At home I use a wireless network, with a USR8540 router. 1 of the laptops has a USR5410 wireless adapter, the other one a Aironet 350.

Now for the good part. I swear I got them both working out of the box. I installed Edgy from CD, aptitude upgrade (va a wired connection) and then inserted the wireless cards. Filled out the configuration for my wireless netwerk in /etc/networking/interfaces, sudo ifup eth1=whome et voila.

But a few days ago, things stopped working: I connect to the router (router log: wireless PC connected), but the dhcp request just does not seem to get to the router. So I end up with the infamous 'No DHCPOFFER received'... I updated the WEP and router MAC access already a couple of times, but alas.
* iwlist scan gives me my home network
* iwconfig eth1 tells me I am connected to my router (my router confirms)
* sudo ifdown eth1 && sudo ifup eth1=whome does not help
* sudo ifdown eth0 && sudo ifdown eth1 && sudo ifup eth1=whome does not help either

My personal laptop is a AMD64, with integrated bcm, which I drive via ndiswrapper. This laptop has Dapper Drake installed onto it, and does not have a problem (yet?).

As far as the NetworkManager is concerned: no I do not use it. I have given it a couple of tries on my laptop on breezy, but couldn't connect to anything anymore. I gave it another try on my kids' laptop, but no go. Either I am missing something, my hardware sucks, I am a terrible kludge, or this package is not mature enough.

If you have upgraded to Edgy, you might want to give network manager a shot. Breezy was using version 0.4.1+cvs20050817-0ubuntu4 of network manager, where Edgy is using 0.6.3-2ubuntu6

So it might be working a whole lot better for you.

Exactly my idea. That's why I gave it another go on the edgy laptop. And I must admit: it has come a long way, but it's not there yet. I wanted to use it for my kids, but I found myself helping them out even more than with a simple script.
Actually, I think the interfaces file is not that bad at all: I have lots of configs stashed in there for all clients I am visiting. A simple command like sudo ifup eth0=<clientconfig> and I am up and running.
Sa as I said before: it did not work for me.