我有一台 Linksys WRT54G 无线路由器，设置为接入点。它通过电缆连接到我们的主路由器（和 DHCP 服务器），然后连接到网络。两端的电缆连接指示灯都亮着。
使用 Kubuntu 9.04、NetworkManager 以及 knetworkmanager 和 nm-applet，我似乎无法连接到网络。“物理”wlan 连接可以工作，但卡在 DHCP 上。
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).
使用 Wireshark 我看到 DHCP 请求已发送，但未收到答复。
我将另一台路由器设置为接入点，也通过电缆连接到主路由器，并且运行正常。这是同一个网络，同一个 DHCP 服务器。我以前也可以连接到现在不工作的 AP。
答案1
9.04 NMapplet 已知存在无线适配器问题。首先使用 cli iwconfig 以成功验证并与无线路由器建立连接。然后您可以执行 ifdown + ifup wlan0。您应该使用 DHCP 获取 IP。
答案2
升级到 9.10 解决了这个问题，以及我之前未解决的一些其他超级用户问题 :D