PING dongduk.ac.kr (210.121.137.144) 56(84) bytes of data.
64 bytes from 210.121.137.144 (210.121.137.144): icmp_seq=1 ttl=52 time=245 ms
64 bytes from 210.121.137.144 (210.121.137.144): icmp_seq=2 ttl=52 time=244 ms
64 bytes from 210.121.137.144 (210.121.137.144): icmp_seq=3 ttl=52 time=244 ms

--- dongduk.ac.kr ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 1999ms
rtt min/avg/max/mdev = 244.392/244.873/245.692/0.815 ms