问题
I am using Cent OS 6.4 and it is in a official lab.
ping google.com gives the below output and hangs:
[root@LAB1 ~]# ping google.com
PING google.com (74.125.236.195) 56(84) bytes of data.
ping 8.8.8.8 also yields the same result. I am able to access internet from browser(Mozilla). Is there a problem with the network settings or configuration?
Below is the output from traceroute - n 8.8.8.8
[root@LAB1 ~]# traceroute -n 8.8.8.8
traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets
1 * * *
2 * * *
3 * * *
4 * * *
5 * * *
6 *^Z
Below is the output from route -n if it helps
[root@LAB1 ~]# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
As I am new to networking, I am not able to identify the issue. Any help here is much appreciated...
Edit : The main reason for me to try the above ping is to resolve an yum update command that fails to resolve the mirror sites...
回答1:
ICMP is'nt allowed outgoing through the firewall / router behind you are accessing Internet.
This
[root@LAB1 ~]# ping google.com
PING google.com (74.125.236.195) 56(84) bytes of data.
And the fact you can browse the web means you are resolving google.com (DNS protocol)
traceroute use ICMP two.
来源：https://stackoverflow.com/questions/19962649/ping-google-com-or-8-8-8-8-fails