一周前安装 Ubuntu 12.04 后，无线互联网一直运行良好。然而，昨天它停止工作了，即使浏览了类似问题的回复，我仍然不知道该怎么办。
我尝试使用 Google 的公共 DNS 并关闭 Firefox 上的代理设置。我使用 nm-tool 和 lshw 来确保我的无线设备和驱动程序已连接。如果有人能帮助我解决这个问题，我将不胜感激！
输出：
$ ping -c3 www.google.com
ping: unknown host www.google.com
$ ping -c4 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
From 192.168.1.104 icmp_seq=1 Destination Host Unreachable
...
--- 8.8.8.8 ping statistics ---
4 packets transmitted, 0 received, +4 errors, 100% packet loss, time 3014ms
$ cat /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 127.0.0.1
$ nm-tool | grep DNS
DNS: 192.168.1.1
$ route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 wlan0
169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 wlan0
192.168.1.0 0.0.0.0 255.255.255.0 U 2 0 0 wlan0
$ ping -c4 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data
From 192.168.1.104 icmp_seq=1 Destination Host Unavailable
From 192.168.1.104 icmp_seq=2 Destination Host Unavailable
--- 192.168.1.1 ping statistics ---
4 packets transmitted, 0 received, +2 errors, 100% packet loss, time 2998ms
pipe 4
$ ifconfig
eth0 Link encap:Ethernet HWaddr 88:ae:1d:58:9d:0b
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)
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:235 errors:0 dropped:0 overruns:0 frame:0
TX packets:235 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:16266 (16.2 KB) TX bytes:16266 (16.2 KB)
wlan0 Link encap:Ethernet HWaddr 00:23:15:35:ce:2c
inet addr:192.168.1.104 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::223:15ff:fe35:ce2c/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:420 errors:0 dropped:0 overruns:0 frame:0
TX packets:264 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:109306 (109.3 KB) TX bytes:27642 (27.6 KB)
wmax0 Link encap:Ethernet HWaddr 64:64:da:04:52:b5
UP NOARP MTU:1400 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:20
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
$ cat /etc/network/interfaces
auto lo
iface lo inet loopback
$ sudo lshw -C network
*-network
description: Ethernet interface
product: RTL8101E/RTL8102E PCI Express Fast Ethernet controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:01:00.0
logical name: eth0
version: 05
serial: 88:ae:1d:58:9d:0b
size: 10Mbit/s
capacity: 100Mbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl_nic/rtl8168e-2.fw
latency=0 link=no multicast=yes port=MII speed=10Mbit/s
resources: irq:41 ioport:6000(size=256) memory:d0404000-d0404fff memory:d0400000-d0403fff
*-network
description: Wireless interface
product: Centrino Advanced-N + WiMAX 6250
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:06:00.0
logical name: wlan0
version: 57
serial: 00:23:15:35:ce:2c
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=iwlwifi driverversion=3.5.0-34-generic firmware=41.28.5.1 build 33926 ip=192.168.1.104 latency=0 link=yes multicast=yes wireless=IEEE 802.11abgn
resources: irq:43 memory:d4600000-d4601fff
*-network
description: Ethernet interface
physical id: 2
logical name: wmx0
serial: 64:d4:da:04:52:b5
capabilities: ethernet physical
configuration: driver=i2400m_usb firmware=i6050-fw-usb-1.5.sbcf link=no
$ dmesg | grep iwl
[ 15.388067] iwlwifi: Intel(R) Wireless WiFi Link AGN driver for Linux, in-tree:
[ 15.388072] iwlwifi: Copyright(c) 2003-2012 Intel Corporation
[ 15.388180] iwlwifi 0000:06:00.0: pci_resource_len = 0x00002000
[ 15.388183] iwlwifi 0000:06:00.0: pci_resource_base = ffffc9000067c000
[ 15.388186] iwlwifi 0000:06:00.0: HW Revision ID = 0x57
[ 15.388263] iwlwifi 0000:06:00.0: irq 43 for MSI/MSI-X
[ 15.391065] iwlwifi 0000:06:00.0: loaded firmware version 41.28.5.1 build 33926
[ 15.391352] iwlwifi 0000:06:00.0: CONFIG_IWLWIFI_DEBUG disabled
[ 15.391356] iwlwifi 0000:06:00.0: CONFIG_IWLWIFI_DEBUGFS enabled
[ 15.391358] iwlwifi 0000:06:00.0: CONFIG_IWLWIFI_DEVICE_TRACING enabled
[ 15.391360] iwlwifi 0000:06:00.0: CONFIG_IWLWIFI_DEVICE_TESTMODE enabled
[ 15.391362] iwlwifi 0000:06:00.0: CONFIG_IWLWIFI_P2P disabled
[ 15.391365] iwlwifi 0000:06:00.0: Detected Intel(R) Centrino(R) Advanced-N + WiMAX 6250 AGN, REV=0x84
[ 15.391427] iwlwifi 0000:06:00.0: L1 Enabled; Disabling L0S
[ 15.399876] iwlwifi 0000:06:00.0: device EEPROM VER=0x552, CALIB=0x6
[ 15.399880] iwlwifi 0000:06:00.0: Device SKU: 0x1F0
[ 15.399883] iwlwifi 0000:06:00.0: Valid Tx ant: 0x3, Valid Rx ant: 0x3
[ 15.399910] iwlwifi 0000:06:00.0: Tunable channels: 13 802.11bg, 24 802.11a channels
[ 15.510715] ieee80211 phy0: Selected rate control algorithm 'iwl-agn-rs'
[ 18.862936] iwlwifi 0000:06:00.0: L1 Enabled; Disabling L0S
[ 18.863126] iwlwifi 0000:06:00.0: Radio type=0x1-0x2-0x0
[ 19.106527] iwlwifi 0000:06:00.0: L1 Enabled; Disabling L0S
[ 19.106721] iwlwifi 0000:06:00.0: Radio type=0x1-0x2-0x0
[ 3754.102289] iwlwifi 0000:06:00.0: RF_KILL bit toggled to disable radio.
[ 3754.102506] iwlwifi 0000:06:00.0: Not sending command - RF KILL
[ 3754.103049] iwlwifi 0000:06:00.0: Not sending command - RF KILL
[ 3754.114930] iwlwifi 0000:06:00.0: Not sending command - RF KILL
[ 3754.114945] iwlwifi 0000:06:00.0: Not sending command - RF KILL
[ 3754.114957] iwlwifi 0000:06:00.0: Not sending command - RF KILL
[ 3754.115002] iwlwifi 0000:06:00.0: Not sending command - RF KILL
[ 3754.115039] iwlwifi 0000:06:00.0: Not sending command - RF KILL
[ 3754.115049] iwlwifi 0000:06:00.0: Not sending command - RF KILL
[ 3754.116099] iwlwifi 0000:06:00.0: Not sending command - RF KILL
[ 3754.128114] iwlwifi 0000:06:00.0: Not sending command - RF KILL
[ 3754.138152] iwlwifi 0000:06:00.0: Not sending command - RF KILL
[ 3756.419608] iwlwifi 0000:06:00.0: RF_KILL bit toggled to enable radio.
[ 3756.421101] iwlwifi 0000:06:00.0: L1 Enabled; Disabling L0S
[ 3756.421286] iwlwifi 0000:06:00.0: Radio type=0x1-0x2-0x0
[ 3762.839399] iwlwifi 0000:06:00.0: RF_KILL bit toggled to disable radio.
[ 3762.840221] iwlwifi 0000:06:00.0: Not sending command - RF KILL
[ 3776.333700] iwlwifi 0000:06:00.0: RF_KILL bit toggled to enable radio.
[ 3776.335758] iwlwifi 0000:06:00.0: L1 Enabled; Disabling L0S
[ 3776.335951] iwlwifi 0000:06:00.0: Radio type=0x1-0x2-0x0
[ 4214.253483] iwlwifi 0000:06:00.0: L1 Enabled; Disabling L0S
[ 4214.253686] iwlwifi 0000:06:00.0: Radio type=0x1-0x2-0x0
[ 4305.514303] iwlwifi 0000:06:00.0: L1 Enabled; Disabling L0S
[ 4305.514509] iwlwifi 0000:06:00.0: Radio type=0x1-0x2-0x0
答案1
我遇到了同样的问题，内置网络连接管理器说一切正常，ifconfig 报告了正确的网络地址并且连接已启动并正在运行，我可以从 PC ping 我的笔记本电脑，但无法访问互联网。
就我而言，这是因为还有一个 GUI 网络管理器 Wicd，它一定是拦截了连接，因为通过 GUI 界面启用无线局域网后，互联网访问就恢复了。
希望这可以帮助。