新手问题 github 能 ping 通，上不去。。。。。
✗ ping github.com
PING github.com (207.97.227.239): 56 data bytes
64 bytes from 207.97.227.239: icmp_seq=0 ttl=47 time=262.712 ms
64 bytes from 207.97.227.239: icmp_seq=1 ttl=47 time=262.690 ms
64 bytes from 207.97.227.239: icmp_seq=2 ttl=47 time=262.594 ms
64 bytes from 207.97.227.239: icmp_seq=3 ttl=47 time=262.349 ms
64 bytes from 207.97.227.239: icmp_seq=4 ttl=47 time=262.630 ms
64 bytes from 207.97.227.239: icmp_seq=5 ttl=47 time=262.454 ms
能 ping 通，上不去。。。。。
