我昨天刚刚在联想笔记本电脑上安装了 Ubuntu，但互联网似乎从来都无法访问。这台笔记本电脑还运行着 Win10，连接完全没有问题。
软件是 Ubuntu 16.04 LTS。基本上，主要问题是，它能够连接到路由器，但仍然不允许外部连接。例如，ping google.com 只会显示“未知主机”或“无法访问主机”。我也无法 ping 我的本地网关 (192.168.2.1)。我已尽可能禁用 ipv6，ipv4 设置在 DHCP 上。现在到了奇怪的部分；有时路由器重启后几分钟它可能会工作，但如果我在这段时间内重启电脑，它就会再次停止工作。路由器显示电脑已连接到路由器。
输出
cat /etc/lsb-release; uname -a
lspci -nnk | grep -iA2 net
lsusb
iwconfig
rfkill list all
lsmod
如下：
xaotic@memecat:~$ cat /etc/lsb-release; uname -a
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=16.04
DISTRIB_CODENAME=xenial
DISTRIB_DESCRIPTION="Ubuntu 16.04.1 LTS"
Linux memecat 4.4.0-31-generic #50-Ubuntu SMP Wed Jul 13 00:07:12 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
xaotic@memecat:~$ lspci -nnk | grep -iA2 net
01:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8821AE 802.11ac PCIe Wireless Network Adapter [10ec:8821]
Subsystem: Lenovo RTL8821AE 802.11ac PCIe Wireless Network Adapter [17aa:a814]
Kernel driver in use: rtl8821ae
Kernel modules: rtl8821ae
02:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller [10ec:8136] (rev 07)
Subsystem: Lenovo RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller [17aa:381e]
Kernel driver in use: r8169
Kernel modules: r8169
xaotic@memecat:~$ lsusb
Bus 002 Device 004: ID 5986:06b3 Acer, Inc
Bus 002 Device 003: ID 0bda:0821 Realtek Semiconductor Corp.
Bus 002 Device 002: ID 0438:7900 Advanced Micro Devices, Inc.
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
Bus 001 Device 004: ID 24db:3257
Bus 001 Device 002: ID 0438:7900 Advanced Micro Devices, Inc.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
xaotic@memecat:~$ iwconfig
enp2s0 no wireless extensions.
lo no wireless extensions.
wlp1s0 IEEE 802.11abgn ESSID:"WLAN-126827"
Mode:Managed Frequency:5.5 GHz Access Point: 84:9C:A6:D7:63:2D
Bit Rate=6 Mb/s Tx-Power=20 dBm
Retry short limit:7 RTS thr=2347 B Fragment thr:off
Power Management:off
Link Quality=70/70 Signal level=-34 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0
xaotic@memecat:~$ rfkill list all
0: ideapad_wlan: Wireless LAN
Soft blocked: no
Hard blocked: no
1: ideapad_bluetooth: Bluetooth
Soft blocked: yes
Hard blocked: no
2: hci0: Bluetooth
Soft blocked: yes
Hard blocked: no
3: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
xaotic@memecat:~$ lsmod
Module Size Used by
uas 24576 0
usb_storage 69632 2 uas
rfcomm 69632 0
drbg 32768 1
ansi_cprng 16384 0
ctr 16384 2
ccm 20480 2
bnep 20480 2
nls_iso8859_1 16384 2
rtsx_usb_ms 20480 0
memstick 20480 1 rtsx_usb_ms
uvcvideo 90112 0
videobuf2_vmalloc 16384 1 uvcvideo
videobuf2_memops 16384 1 videobuf2_vmalloc
videobuf2_v4l2 28672 1 uvcvideo
kvm 536576 0
videobuf2_core 36864 2 uvcvideo,videobuf2_v4l2
v4l2_common 16384 1 videobuf2_v4l2
irqbypass 16384 1 kvm
videodev 176128 4 uvcvideo,v4l2_common,videobuf2_core,videobuf2_v4l2
crct10dif_pclmul 16384 0
crc32_pclmul 16384 0
snd_hda_codec_realtek 86016 1
arc4 16384 2
media 24576 2 uvcvideo,videodev
aesni_intel 167936 4
aes_x86_64 20480 1 aesni_intel
rtl8821ae 225280 0
lrw 16384 1 aesni_intel
gf128mul 16384 1 lrw
snd_hda_codec_generic 77824 1 snd_hda_codec_realtek
snd_hda_codec_hdmi 53248 1
btcoexist 53248 1 rtl8821ae
glue_helper 16384 1 aesni_intel
snd_hda_intel 36864 5
snd_hda_codec 135168 4 snd_hda_codec_realtek,snd_hda_codec_hdmi,snd_hda_codec_generic,snd_hda_intel
rtl_pci 28672 1 rtl8821ae
rtlwifi 77824 2 rtl_pci,rtl8821ae
btusb 45056 0
snd_hda_core 73728 5 snd_hda_codec_realtek,snd_hda_codec_hdmi,snd_hda_codec_generic,snd_hda_codec,snd_hda_intel
ablk_helper 16384 1 aesni_intel
mac80211 737280 3 rtl_pci,rtlwifi,rtl8821ae
snd_hwdep 16384 1 snd_hda_codec
cryptd 20480 2 aesni_intel,ablk_helper
btrtl 16384 1 btusb
snd_pcm 106496 4 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel,snd_hda_core
cfg80211 565248 2 mac80211,rtlwifi
ideapad_laptop 24576 0
btbcm 16384 1 btusb
snd_seq_midi 16384 0
snd_seq_midi_event 16384 1 snd_seq_midi
snd_rawmidi 32768 1 snd_seq_midi
btintel 16384 1 btusb
sparse_keymap 16384 1 ideapad_laptop
wmi 20480 1 ideapad_laptop
snd_seq 69632 2 snd_seq_midi_event,snd_seq_midi
bluetooth 520192 29 bnep,btbcm,btrtl,btusb,rfcomm,btintel
input_leds 16384 0
joydev 20480 0
snd_seq_device 16384 3 snd_seq,snd_rawmidi,snd_seq_midi
snd_timer 32768 2 snd_pcm,snd_seq
edac_mce_amd 24576 0
snd 81920 21 snd_hda_codec_realtek,snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_pcm,snd_seq,snd_rawmidi,snd_hda_codec_generic,snd_hda_codec,snd_hda_intel,snd_seq_device
soundcore 16384 1 snd
serio_raw 16384 0
fam15h_power 16384 0
shpchp 36864 0
edac_core 53248 0
k10temp 16384 0
acpi_als 16384 0
i2c_piix4 24576 0
ccp 36864 0
kfifo_buf 16384 1 acpi_als
industrialio 57344 2 acpi_als,kfifo_buf
mac_hid 16384 0
tpm_crb 16384 0
parport_pc 32768 0
ppdev 20480 0
lp 20480 0
parport 49152 3 lp,ppdev,parport_pc
autofs4 40960 2
rtsx_usb_sdmmc 28672 0
rtsx_usb 24576 2 rtsx_usb_sdmmc,rtsx_usb_ms
amdkfd 131072 1
amd_iommu_v2 20480 1 amdkfd
radeon 1515520 3
psmouse 126976 0
i2c_algo_bit 16384 1 radeon
ttm 94208 1 radeon
drm_kms_helper 147456 1 radeon
syscopyarea 16384 1 drm_kms_helper
sysfillrect 16384 1 drm_kms_helper
sysimgblt 16384 1 drm_kms_helper
fb_sys_fops 16384 1 drm_kms_helper
drm 360448 51 ttm,drm_kms_helper,radeon
r8169 81920 0
ahci 36864 3
mii 16384 1 r8169
libahci 32768 1 ahci
video 40960 1 ideapad_laptop
fjes 28672 0
输出ifconfig：
xaotic@memecat:~$ ifconfig
enp2s0 Link encap:Ethernet HWaddr 50:7b:9d:fe:6d:50
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:65536 Metric:1
RX packets:269 errors:0 dropped:0 overruns:0 frame:0
TX packets:269 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:20778 (20.7 KB) TX bytes:20778 (20.7 KB)
wlp1s0 Link encap:Ethernet HWaddr 30:f7:72:33:2c:63
inet addr:192.168.2.107 Bcast:192.168.2.255 Mask:255.255.255.0
inet6 addr: fe80::c7d:e090:bd1e:69e8/64 Scope:Link
inet6 addr: 2003:74:f6f:7dbe:c5a2:fa84:d379:7e87/64 Scope:Global
inet6 addr: 2003:74:f6f:7dbe:5c70:4b04:d868:dc97/64 Scope:Global
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:101 errors:0 dropped:0 overruns:0 frame:0
TX packets:194 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:20101 (20.1 KB) TX bytes:26815 (26.8 KB)
/etc/network/interfaces
# interfaces(t) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback
（没有 eth0 或 wlan0 条目？）并且 ping ：
xaotic@memecat:~$ ping google.com
ping: unknown host google.com
任何帮助都将不胜感激，非常感谢！