PING expire.dmctr.cn (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.013 ms
64 bytes from localhost (127.0.0.1): icmp_seq=2 ttl=64 time=0.032 ms
64 bytes from localhost (127.0.0.1): icmp_seq=3 ttl=64 time=0.037 ms

--- expire.dmctr.cn ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2025ms
rtt min/avg/max/mdev = 0.013/0.027/0.037/0.011 ms