我正在尝试通过有线连接连接到我工作的大学的局域网。 连接到网络后，通过VPN访问互联网。
在 Windows 7 上，插入以太网电缆后，计算机似乎会自动通过 DHCP 连接到网络，并列出相关的 VPN，以便我可以输入用户名和密码。
在 Ubuntu 12.10 上，VPN 甚至不是问题，因为 NetworkManager 甚至无法完成 DHCP 事务以先连接到 LAN。
sudo lspci -v：
00:19.0 Ethernet controller: Intel Corporation 82567LM Gigabit Network Connection (rev 03)
Subsystem: Lenovo Device 20ee
Flags: bus master, fast devsel, latency 0, IRQ 45
Memory at fc600000 (32-bit, non-prefetchable) [size=128K]
Memory at fc625000 (32-bit, non-prefetchable) [size=4K]
I/O ports at 1840 [size=32]
Capabilities: [c8] Power Management version 2
Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [e0] PCI Advanced Features
Kernel driver in use: e1000e
Kernel modules: e1000e
ifconfig -a：
eth0 Link encap:Ethernet HWaddr 00:1c:25:98:6e:8a
inet6 addr: fe80::21c:25ff:fe98:6e8a/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:162 errors:0 dropped:0 overruns:0 frame:0
TX packets:484 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:10368 (10.3 KB) TX bytes:128521 (128.5 KB)
Interrupt:20 Memory:fc600000-fc620000
相关系统日志信息：
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Auto-activating connection 'Auto Ethernet'.
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) starting connection 'Auto Ethernet'
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: (eth0): device state change: disconnected -> prepare (reason 'none') [30 40 0]
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 1 of 5 (Device Prepare) scheduled...
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 1 of 5 (Device Prepare) started...
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 2 of 5 (Device Configure) scheduled...
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 1 of 5 (Device Prepare) complete.
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 2 of 5 (Device Configure) starting...
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: (eth0): device state change: prepare -> config (reason 'none') [40 50 0]
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 2 of 5 (Device Configure) successful.
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 3 of 5 (IP Configure Start) scheduled.
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 2 of 5 (Device Configure) complete.
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 3 of 5 (IP Configure Start) started...
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: (eth0): device state change: config -> ip-config (reason 'none') [50 70 0]
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Beginning DHCPv4 transaction (timeout in 45 seconds)
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: dhclient started with pid 3062
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Beginning IP6 addrconf.
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 3 of 5 (IP Configure Start) complete.
Nov 29 22:06:37 a-ThinkPad-T400 dhclient: Internet Systems Consortium DHCP Client 4.2.4
Nov 29 22:06:37 a-ThinkPad-T400 dhclient: Copyright 2004-2012 Internet Systems Consortium.
Nov 29 22:06:37 a-ThinkPad-T400 dhclient: All rights reserved.
Nov 29 22:06:37 a-ThinkPad-T400 dhclient: For info, please visit https://www.isc.org/software/dhcp/
Nov 29 22:06:37 a-ThinkPad-T400 dhclient:
Nov 29 22:06:37 a-ThinkPad-T400 NetworkManager[812]: (eth0): DHCPv4 state changed nbi -> preinit
Nov 29 22:06:37 a-ThinkPad-T400 dhclient: Listening on LPF/eth0/00:1c:25:98:6e:8a
Nov 29 22:06:37 a-ThinkPad-T400 dhclient: Sending on LPF/eth0/00:1c:25:98:6e:8a
Nov 29 22:06:37 a-ThinkPad-T400 dhclient: Sending on Socket/fallback
Nov 29 22:06:37 a-ThinkPad-T400 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3
Nov 29 22:06:38 a-ThinkPad-T400 avahi-daemon[542]: Joining mDNS multicast group on interface eth0.IPv6 with address fe80::21c:25ff:fe98:6e8a.
Nov 29 22:06:38 a-ThinkPad-T400 avahi-daemon[542]: New relevant interface eth0.IPv6 for mDNS.
Nov 29 22:06:38 a-ThinkPad-T400 avahi-daemon[542]: Registering new address record for fe80::21c:25ff:fe98:6e8a on eth0.*.
Nov 29 22:06:40 a-ThinkPad-T400 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3
Nov 29 22:06:43 a-ThinkPad-T400 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
Nov 29 22:06:51 a-ThinkPad-T400 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 12
Nov 29 22:06:57 a-ThinkPad-T400 NetworkManager[812]: (eth0): IP6 addrconf timed out or failed.
Nov 29 22:06:57 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 4 of 5 (IPv6 Configure Timeout) scheduled...
Nov 29 22:06:57 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 4 of 5 (IPv6 Configure Timeout) started...
Nov 29 22:06:57 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 4 of 5 (IPv6 Configure Timeout) complete.
Nov 29 22:07:03 a-ThinkPad-T400 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 12
Nov 29 22:07:15 a-ThinkPad-T400 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 20
Nov 29 22:07:22 a-ThinkPad-T400 NetworkManager[812]: (eth0): DHCPv4 request timed out.
Nov 29 22:07:23 a-ThinkPad-T400 NetworkManager[812]: (eth0): canceled DHCP transaction, DHCP client pid 3062
Nov 29 22:07:23 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 4 of 5 (IPv4 Configure Timeout) scheduled...
Nov 29 22:07:23 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 4 of 5 (IPv4 Configure Timeout) started...
Nov 29 22:07:23 a-ThinkPad-T400 NetworkManager[812]: (eth0): device state change: ip-config -> failed (reason 'ip-config-unavailable') [70 120 5]
Nov 29 22:07:23 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) failed for connection 'Auto Ethernet'
Nov 29 22:07:23 a-ThinkPad-T400 NetworkManager[812]: Activation (eth0) Stage 4 of 5 (IPv4 Configure Timeout) complete.
Nov 29 22:07:23 a-ThinkPad-T400 NetworkManager[812]: (eth0): device state change: failed -> disconnected (reason 'none') [120 30 0]
Nov 29 22:07:23 a-ThinkPad-T400 NetworkManager[812]: (eth0): deactivating device (reason 'none') [0]
Nov 29 22:07:23 a-ThinkPad-T400 avahi-daemon[542]: Withdrawing address record for fe80::21c:25ff:fe98:6e8a on eth0.
Nov 29 22:07:23 a-ThinkPad-T400 avahi-daemon[542]: Leaving mDNS multicast group on interface eth0.IPv6 with address fe80::21c:25ff:fe98:6e8a.
Nov 29 22:07:23 a-ThinkPad-T400 avahi-daemon[542]: Interface eth0.IPv6 no longer relevant for mDNS.