O comando Ping resulta na perda de pacotes

Question

Sempre que eu ping no meu computador pessoal, nada é exibido além de uma única instrução.

Ao parar a execução, vejo que vários pacotes foram transmitidos nas estatísticas. Além de tudo isso, estou recebendo uma perda absurda de pacotes.

O que posso fazer para que ping reaja de maneira sã?

Estou executando o Centos 6.5 64bit .

Abaixo está um exemplo de saída quando eu tento ping google.com :

[root@Virus os]# ping google.com
PING google.com (74.125.230.160) 56(84) bytes of data.
^C
--- google.com ping statistics ---
5 packets transmitted, 0 received, 100% packet loss, time 4274ms

ifconfig -a :

[root@Virus os]# ifconfig -a
eth0      Link encap:Ethernet  HWaddr B4:B5:2F:29:FE:D7  
          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:108 errors:0 dropped:0 overruns:0 frame:0
          TX packets:108 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:9081 (8.8 KiB)  TX bytes:9081 (8.8 KiB)

wlan0     Link encap:Ethernet  HWaddr 84:4B:F5:14:9B:58  
          inet addr:172.20.40.55  Bcast:172.20.255.255  Mask:255.255.0.0
          inet6 addr: fe80::864b:f5ff:fe14:9b58/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:56944 errors:0 dropped:0 overruns:0 frame:0
          TX packets:40200 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:55308863 (52.7 MiB)  TX bytes:6291284 (5.9 MiB)

iptables -L :

[root@Virus www]# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination         
ACCEPT     all  --  anywhere             anywhere            state RELATED,ESTABLISHED 
ACCEPT     icmp --  anywhere             anywhere            
ACCEPT     all  --  anywhere             anywhere            
ACCEPT     tcp  --  anywhere             anywhere            state NEW tcp dpt:ssh 
REJECT     all  --  anywhere             anywhere            reject-with icmp-host-prohibited 

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         
REJECT     all  --  anywhere             anywhere            reject-with icmp-host-prohibited 

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination 

netstat -nr :

[root@Virus www]# netstat -nr
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
172.20.0.0      0.0.0.0         255.255.0.0     U         0 0          0 wlan0
0.0.0.0         172.20.4.254    0.0.0.0         UG        0 0          0 wlan0