PING wr.lib.tsinghua.edu.cn (101.6.6.219) 56(84) bytes of data.
64 bytes from 101.6.6.219 (101.6.6.219): icmp_seq=1 ttl=49 time=282 ms
64 bytes from 101.6.6.219 (101.6.6.219): icmp_seq=2 ttl=49 time=282 ms
64 bytes from 101.6.6.219 (101.6.6.219): icmp_seq=3 ttl=49 time=281 ms

--- wr.lib.tsinghua.edu.cn ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2040ms
rtt min/avg/max/mdev = 281.961/282.293/282.898/0.748 ms