Linux NetworkManager can't connect

Question

I have a Linksys WRT54G wlan router set up as an access point. It's connected via cable to our main router (and DHCP server) which connects to the net. The cable connection indicator light is on, on both ends.

Using Kubuntu 9.04, NetworkManager and both knetworkmanager and nm-applet, I cannot seem to connect to the network. The "physical" wlan connection works, but it gets stuck on DHCP.

Sep 23 00:40:48 bart-laptop NetworkManager: <info>  Activation (wlan0) Beginning DHCP transaction.
Sep 23 00:40:48 bart-laptop dhclient: Internet Systems Consortium DHCP Client V3.1.1
Sep 23 00:40:48 bart-laptop dhclient: Copyright 2004-2008 Internet Systems Consortium.
Sep 23 00:40:48 bart-laptop dhclient: All rights reserved.
Sep 23 00:40:48 bart-laptop dhclient: For info, please visit http://www.isc.org/sw/dhcp/
Sep 23 00:40:48 bart-laptop dhclient:
Sep 23 00:40:48 bart-laptop dhclient: wmaster0: unknown hardware address type 801
Sep 23 00:40:48 bart-laptop NetworkManager: <info>  dhclient started with pid 31223
Sep 23 00:40:48 bart-laptop NetworkManager: <info>  Activation (wlan0) Stage 3 of 5 (IP Configure Start) complete.
Sep 23 00:40:48 bart-laptop NetworkManager: <info>  DHCP: device wlan0 state changed normal exit -> preinit
Sep 23 00:40:48 bart-laptop dhclient: wmaster0: unknown hardware address type 801
Sep 23 00:40:48 bart-laptop dhclient: Listening on LPF/wlan0/00:21:6a:16:0c:50
Sep 23 00:40:48 bart-laptop dhclient: Sending on   LPF/wlan0/00:21:6a:16:0c:50
Sep 23 00:40:48 bart-laptop dhclient: Sending on   Socket/fallback
Sep 23 00:40:48 bart-laptop dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 6
Sep 23 00:40:54 bart-laptop dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 13
Sep 23 00:41:07 bart-laptop dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 15
Sep 23 00:41:22 bart-laptop dhclient: DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 12
Sep 23 00:41:34 bart-laptop NetworkManager: <info>  Device 'wlan0' DHCP transaction took too long (>45s), stopping it.
Sep 23 00:41:34 bart-laptop NetworkManager: <info>  wlan0: canceled DHCP transaction, dhcp client pid 31223
Sep 23 00:41:34 bart-laptop NetworkManager: <info>  Activation (wlan0) Stage 4 of 5 (IP Configure Timeout) scheduled...
Sep 23 00:41:34 bart-laptop NetworkManager: <info>  Activation (wlan0) Stage 4 of 5 (IP Configure Timeout) started...
Sep 23 00:41:34 bart-laptop NetworkManager: <info>  (wlan0): device state change: 7 -> 9
Sep 23 00:41:34 bart-laptop NetworkManager: <info>  Activation (wlan0) failed for access point (VanHeukelom2)
Sep 23 00:41:34 bart-laptop NetworkManager: <info>  Marking connection 'Auto VanHeukelom2' invalid.
Sep 23 00:41:34 bart-laptop NetworkManager: <info>  Activation (wlan0) failed.
Sep 23 00:41:34 bart-laptop NetworkManager: <info>  Activation (wlan0) Stage 4 of 5 (IP Configure Timeout) complete.
Sep 23 00:41:34 bart-laptop NetworkManager: <info>  (wlan0): device state change: 9 -> 3
Sep 23 00:41:34 bart-laptop NetworkManager: <info>  (wlan0): deactivating device (reason: 0).

Using Wireshark I see that a DHCP request is sent, but no answer is received.

I have another router set up as access point, also connected to the main router via a cable, and that works fine. It's the same network, the same DHCP server. I could also connect to the now not working AP in the past.

Answer 1

An upgrade to 9.10 fixed this, along with some of my other previously unfixed superuser questions :D

Answer 2

The 9.04 NMapplet is known to have issues with wireless adapters. First use cli iwconfig inorder to successfully authenticate and establish connectivity with the wireless router. Then you can do ifdown + ifup wlan0. You should get the IP with DHCP.