我一直在双启动的 Lenovo Thinkpad Edge 上使用 12.04。最近，Wi-Fi 在我的家庭网络上停止工作，但在开放网络上仍可工作。家中的其他计算机和我的 ThinkPad 从 Windows 分区启动时运行良好。
检查系统日志表明计算机能够连接，但在 DHCP 协商期间断开连接。
有线连接可以正常工作，所以我登录路由器并禁用了安全功能。然后 Wi-Fi 工作正常。但是，让网络保持畅通不是一个选择。
检查 /var/log/apt/history.log 发现最近isc-dhcp-common有更新。我怀疑问题就出在这里。
问题是，如果路由器启用了加密，我就无法连接。
有人可以建议我在这里做什么吗？
哈尔多尔
以下是系统日志的相关部分。
16:27:33 NetworkManager[807]: <info> (eth1): bringing up device.
16:27:33 NetworkManager[807]: <info> WiFi hardware radio set enabled
16:27:33 NetworkManager[807]: <info> WiFi now enabled by radio killswitch
16:27:33 NetworkManager[807]: <info> (eth1): bringing up device.
16:27:34 NetworkManager[807]: <info> (eth1): supplicant interface state: starting -> ready
16:27:34 NetworkManager[807]: <info> (eth1): device state change: unavailable -> disconnected (reason 'supplicant-available') [20 30 42]
16:27:34 NetworkManager[807]: <info> (eth1): supplicant interface state: ready -> inactive
16:27:34 NetworkManager[807]: <warn> Trying to remove a non-existant call id.
16:27:35 NetworkManager[807]: <info> Auto-activating connection 'Chipie'.
16:27:35 NetworkManager[807]: <info> Activation (eth1) starting connection 'Chipie'
16:27:35 NetworkManager[807]: <info> (eth1): device state change: disconnected -> prepare (reason 'none') [30 40 0]
16:27:35 NetworkManager[807]: <info> Activation (eth1) Stage 1 of 5 (Device Prepare) scheduled...
16:27:35 NetworkManager[807]: <info> Activation (eth1) Stage 1 of 5 (Device Prepare) started...
16:27:35 NetworkManager[807]: <info> Activation (eth1) Stage 2 of 5 (Device Configure) scheduled...
16:27:35 NetworkManager[807]: <info> Activation (eth1) Stage 1 of 5 (Device Prepare) complete.
16:27:35 NetworkManager[807]: <info> Activation (eth1) Stage 2 of 5 (Device Configure) starting...
16:27:35 NetworkManager[807]: <info> (eth1): device state change: prepare -> config (reason 'none') [40 50 0]
16:27:35 NetworkManager[807]: <info> Activation (eth1/wireless): connection 'Chipie' has security, and secrets exist. No new secrets needed.
16:27:35 NetworkManager[807]: <info> Config: added 'ssid' value 'Chipie'
16:27:35 NetworkManager[807]: <info> Config: added 'scan_ssid' value '1'
16:27:35 NetworkManager[807]: <info> Config: added 'key_mgmt' value 'NONE'
16:27:35 NetworkManager[807]: <info> Config: added 'wep_key0' value '<omitted>'
16:27:35 NetworkManager[807]: <info> Config: added 'wep_tx_keyidx' value '0'
16:27:35 NetworkManager[807]: <info> Activation (eth1) Stage 2 of 5 (Device Configure) complete.
16:27:35 NetworkManager[807]: <info> Config: set interface ap_scan to 1
16:27:35 NetworkManager[807]: <info> (eth1): supplicant interface state: inactive -> scanning
16:27:35 avahi-daemon[809]: Joining mDNS multicast group on interface eth1.IPv6 with address fe80::aed:b9ff:fee2:807d.
16:27:35 avahi-daemon[809]: New relevant interface eth1.IPv6 for mDNS.
16:27:35 avahi-daemon[809]: Registering new address record for fe80::aed:b9ff:fee2:807d on eth1.*.
16:27:36 wpa_supplicant[2352]: Trying to associate with 00:1c:f0:66:23:90 (SSID='Chipie' freq=2412 MHz)
16:27:36 NetworkManager[807]: <info> (eth1): supplicant interface state: scanning -> associating
16:27:36 wpa_supplicant[2352]: Associated with 00:1c:f0:66:23:90
16:27:36 wpa_supplicant[2352]: CTRL-EVENT-CONNECTED - Connection to 00:1c:f0:66:23:90 completed (auth) [id=0 id_str=]
16:27:36 NetworkManager[807]: <info> (eth1): supplicant interface state: associating -> completed
16:27:36 NetworkManager[807]: <info> Activation (eth1/wireless) Stage 2 of 5 (Device Configure) successful. Connected to wireless network 'Chipie'.
16:27:36 NetworkManager[807]: <info> Activation (eth1) Stage 3 of 5 (IP Configure Start) scheduled.
16:27:36 NetworkManager[807]: <info> Activation (eth1) Stage 3 of 5 (IP Configure Start) started...
16:27:36 NetworkManager[807]: <info> (eth1): device state change: config -> ip-config (reason 'none') [50 70 0]
16:27:36 NetworkManager[807]: <info> Activation (eth1) Beginning DHCPv4 transaction (timeout in 45 seconds)
16:27:36 NetworkManager[807]: <info> dhclient started with pid 8724
16:27:36 NetworkManager[807]: <info> Activation (eth1) Beginning IP6 addrconf.
16:27:36 avahi-daemon[809]: Withdrawing address record for fe80::aed:b9ff:fee2:807d on eth1.
16:27:36 avahi-daemon[809]: Leaving mDNS multicast group on interface eth1.IPv6 with address fe80::aed:b9ff:fee2:807d.
16:27:36 avahi-daemon[809]: Interface eth1.IPv6 no longer relevant for mDNS.
16:27:36 NetworkManager[807]: <info> Activation (eth1) Stage 3 of 5 (IP Configure Start) complete.
16:27:36 dhclient: Internet Systems Consortium DHCP Client 4.1-ESV-R4
16:27:36 dhclient: Copyright 2004-2011 Internet Systems Consortium.
16:27:36 dhclient: All rights reserved.
16:27:36 dhclient: For info, please visit https://www.isc.org/software/dhcp/
16:27:36 dhclient:
16:27:36 NetworkManager[807]: <info> (eth1): DHCPv4 state changed nbi -> preinit
16:27:36 dhclient: Listening on LPF/eth1/08:ed:b9:e2:80:7d
16:27:36 dhclient: Sending on LPF/eth1/08:ed:b9:e2:80:7d
16:27:36 dhclient: Sending on Socket/fallback
16:27:36 dhclient: DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 3
16:27:37 avahi-daemon[809]: Joining mDNS multicast group on interface eth1.IPv6 with address fe80::aed:b9ff:fee2:807d.
16:27:37 avahi-daemon[809]: New relevant interface eth1.IPv6 for mDNS.
16:27:37 avahi-daemon[809]: Registering new address record for fe80::aed:b9ff:fee2:807d on eth1.*.
16:27:39 dhclient: DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 3
16:27:46 dhclient: last message repeated 2 times
16:27:46 kernel: [28901.182673] eth1: no IPv6 routers present
16:27:48 dhclient: DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 3
16:27:51 dhclient: DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 8
16:27:56 NetworkManager[807]: <info> (eth1): IP6 addrconf timed out or failed.
16:27:56 NetworkManager[807]: <info> Activation (eth1) Stage 4 of 5 (IPv6 Configure Timeout) scheduled...
16:27:56 NetworkManager[807]: <info> Activation (eth1) Stage 4 of 5 (IPv6 Configure Timeout) started...
16:27:56 NetworkManager[807]: <info> Activation (eth1) Stage 4 of 5 (IPv6 Configure Timeout) complete.
16:27:59 dhclient: DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 11
16:28:04 NetworkManager[807]: <info> (eth1): device state change: ip-config -> unavailable (reason 'none') [70 20 0]
16:28:04 NetworkManager[807]: <info> (eth1): deactivating device (reason 'none') [0]
16:28:04 NetworkManager[807]: <info> (eth1): canceled DHCP transaction, DHCP client pid 8724
16:28:04 avahi-daemon[809]: Withdrawing address record for fe80::aed:b9ff:fee2:807d on eth1.
16:28:04 avahi-daemon[809]: Leaving mDNS multicast group on interface eth1.IPv6 with address fe80::aed:b9ff:fee2:807d.
16:28:04 avahi-daemon[809]: Interface eth1.IPv6 no longer relevant for mDNS.
16:28:04 NetworkManager[807]: <info> Policy set 'Wired connection 1' (eth0) as default for IPv4 routing and DNS.
16:28:04 NetworkManager[807]: <info> Policy set 'Wired connection 1' (eth0) as default for IPv4 routing and DNS.
16:28:04 NetworkManager[807]: <info> (eth1): taking down device.
我还没搞清楚如何解决这个问题。与此同时，只要我使用固定 IP，我就可以使用带 WEP 的 wifii。我只是检查了路由器上有哪些号码可用，然后选择了一个不太可能被选中的号码。设置 dns/掩码/网关，一切就绪。连接顺利。不是一个令人满意的解决方案，但是一种变通方法。
——哈尔多尔
答案1
我以前也遇到过同样的问题。我不是这方面的专家，但你试过使用编辑连接吗？可能是 Ubuntu 中的 Wifi 配置有问题。如果你修复它，你的互联网可能会正常工作。检查 Windows 中使用的确切配置（共享/开放等）。然后在 Ubuntu 中使用完全相同的 Wifi 配置。
答案2
我不是专家，但看起来这可能是 IPv6 寻址的问题。我遇到过类似的问题，并通过关闭 IPv6 解决了它。当然，这并不能真正解决根本问题，根本问题是“为什么 IPv6 寻址不起作用？”但它让我的无线网络再次工作 - 也可能对你有帮助。
从终端：
sudo gedit /etc/sysctl.conf
现在在 sysctl.conf 文件末尾添加以下行：
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.默认.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
保存并关闭，可能需要重新启动。
答案3
查看您的系统日志....
关联成功，但 DHCP 客户端未收到 DHCP 服务器对其 DHCPDISCOVER 数据包的回复。
检查您的 DHCP 服务器配置：它是否设置为拒绝未知的 MAC 地址，并且是否列出了您的 Wi-Fi 接口的 MAC 地址？
答案4
将路由器重新配置为另一种身份验证模式（例如，使用 TKIP 加密的 WPAPSK）。看来 WEP 在许多具有各种驱动程序的 Linux 版本上可能存在问题。
背景：
我在装有联发科驱动程序的华硕笔记本电脑上使用 16.04 时也遇到了类似的问题。我可以连接到其他路由器，但无法连接到设置为使用 WEP 的家用路由器。我尝试了许多建议的解决方案，但都不起作用。最终的解决方案是将路由器重新配置为另一种身份验证模式（在我的情况下是带有 TKIP 加密的 WPAPSK），这为我解决了问题。从其他评论来看，WEP 可能在许多具有各种驱动程序的 Linux 版本上存在问题。因此，如果您遇到 WEP 连接问题，请查看路由器配置而不是 Linux 设置。