How if a machine can not ping outside
来自cslt Wiki
1. check if can ping the gateway. Firstly, 192.168.0.1, and if double ips, 166.111.134.1
2. check the route: netstat -rn or route
3. you need set DEFROUTE='no' for NICs that are not the default route.
4. The problem of #3 happs when grid-1 can not reach outside, and so cvss and bugdb can not send mails.
