Meu Ubuntu não pode acessar a Internet

Question

Meu Ubuntu não pode acessar a Internet, enquanto minha máquina virtual do Windows na Virtual box, que está instalada no meu Ubuntu, pode. A configuração de rede dessa máquina virtual é do tipo bridge de wlan0. Eu não consigo nem pingar o gateway padrão na interface wlan0 do meu Ubuntu, mas tudo funciona bem nessa máquina Windows.

Saída de ifconfig wlan0

      Link encap:Ethernet  HWaddr 60:36:dd:14:d2:3c  
      inet addr:172.30.60.188  Bcast:172.30.60.255  Mask:255.255.255.0
      inet6 addr: fe80::6236:ddff:fe14:d23c/64 Scope:Link
      UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
      RX packets:332314 errors:0 dropped:54 overruns:0 frame:0
      TX packets:43703 errors:0 dropped:0 overruns:0 carrier:0
      collisions:0 txqueuelen:1000 
      RX bytes:66076979 (66.0 MB)  TX bytes:5894865 (5.8 MB)

Saída de route -n

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         172.30.60.1     0.0.0.0         UG    1024   0        0 wlan0
81.31.160.0     172.30.60.1     255.255.224.0   UG    10     0        0 wlan0
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 wlan0
172.30.60.0     0.0.0.0         255.255.255.0   U     0      0        0 wlan0
213.233.160.0   172.30.60.1     255.255.224.0   UG    10     0        0 wlan0

Observe que o ping dessa máquina Windows será respondido muito rapidamente, mas o ping do Ubuntu será respondido muito lentamente.

Fora de ping 172.30.60.1 , este é o gateway padrão.

PING 172.30.60.1 (172.30.60.1) 56(84) bytes of data.
64 bytes from 172.30.60.1: icmp_seq=62 ttl=255 time=43.4 ms
64 bytes from 172.30.60.1: icmp_seq=63 ttl=255 time=3.85 ms
64 bytes from 172.30.60.1: icmp_seq=71 ttl=255 time=4.78 ms
64 bytes from 172.30.60.1: icmp_seq=82 ttl=255 time=2.44 ms
64 bytes from 172.30.60.1: icmp_seq=127 ttl=255 time=2.31 ms
64 bytes from 172.30.60.1: icmp_seq=148 ttl=255 time=154 ms
64 bytes from 172.30.60.1: icmp_seq=217 ttl=255 time=4.06 ms
64 bytes from 172.30.60.1: icmp_seq=225 ttl=255 time=2.97 ms
64 bytes from 172.30.60.1: icmp_seq=333 ttl=255 time=101 ms
64 bytes from 172.30.60.1: icmp_seq=334 ttl=255 time=71.3 ms
64 bytes from 172.30.60.1: icmp_seq=473 ttl=255 time=14.5 ms
64 bytes from 172.30.60.1: icmp_seq=474 ttl=255 time=2.47 ms
64 bytes from 172.30.60.1: icmp_seq=544 ttl=255 time=10.0 ms
64 bytes from 172.30.60.1: icmp_seq=585 ttl=255 time=745 ms
64 bytes from 172.30.60.1: icmp_seq=586 ttl=255 time=488 ms
64 bytes from 172.30.60.1: icmp_seq=587 ttl=255 time=863 ms
64 bytes from 172.30.60.1: icmp_seq=589 ttl=255 time=2048 ms
64 bytes from 172.30.60.1: icmp_seq=590 ttl=255 time=1234 ms
64 bytes from 172.30.60.1: icmp_seq=591 ttl=255 time=227 ms
64 bytes from 172.30.60.1: icmp_seq=592 ttl=255 time=121 ms
^C
--- 172.30.60.1 ping statistics ---
639 packets transmitted, 20 received, 96% packet loss, time 642600ms
rtt min/avg/max/mdev = 2.319/307.380/2048.298/523.403 ms, pipe 3

Como você pode ver, há 96% de perda de pacotes. Esse problema é bem estranho para mim!

Também pode valer a pena mencionar que meu Ubuntu estava funcionando bem até que eu tenha instalado aircrack-ng e wireshark packages.

EDIT # 1

Saída de lspci -knn | grep Net -A2

Network controller [0280]: Intel Corporation Centrino Wireless-N 2230 [8086:0888] (rev c4)
Subsystem: Intel Corporation Centrino Wireless-N 2230 BGN [8086:4262]
Kernel driver in use: iwlwifi

Saída de iwconfig

IEEE 802.11bgn  ESSID:"Shadmaan"  
Mode:Managed  Frequency:2.462 GHz  Access Point: 0A:18:D6:A9:49:FE   
Bit Rate=58.5 Mb/s   Tx-Power=16 dBm   
Retry short limit:7   RTS thr:off   Fragment thr:off
Power Management:on
Link Quality=49/70  Signal level=-61 dBm  
Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
Tx excessive retries:116  Invalid misc:4646   Missed beacon:0

EDIT # 2

A saída FULL de iwconfig

eth0      no wireless extensions.

wlan0     IEEE 802.11bgn  ESSID:"Shadmaan"  
          Mode:Managed  Frequency:2.462 GHz  Access Point: 0A:18:D6:A9:49:FE   
          Bit Rate=58.5 Mb/s   Tx-Power=16 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:on
          Link Quality=49/70  Signal level=-61 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:116  Invalid misc:4646   Missed beacon:0

ppp0      no wireless extensions.

lo        no wireless extensions.

    

Answer 1

Execute isso no terminal

sudo tee /etc/modprobe/iwlwifi-opt.conf <<< "options iwlwifi swcrypto=1 11n_disable=1 bt_coex_active=0 power_save=0"

depois reinicie.

Isso desativará todas as opções problemáticas. Você pode testar se todos eles são necessários editando /etc/modprobe/iwlwifi-opt.conf file.