PING www.cad.zju.edu.cn (210.32.131.211) 56(84) bytes of data.
64 bytes from 211.in-addr.arpa (210.32.131.211): icmp_seq=1 ttl=45 time=275 ms
64 bytes from 211.in-addr.arpa (210.32.131.211): icmp_seq=2 ttl=45 time=290 ms
64 bytes from 211.in-addr.arpa (210.32.131.211): icmp_seq=3 ttl=45 time=297 ms

--- www.cad.zju.edu.cn ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2171ms
rtt min/avg/max/mdev = 275.135/287.860/297.981/9.517 ms