$ ping -n -c 5
l.root-servers.netPING
l.root-servers.net (199.7.83.42) 56(84) bytes of data.
64 bytes from 199.7.83.42: icmp_seq=1 ttl=56 time=10.7 ms
64 bytes from 199.7.83.42: icmp_seq=2 ttl=56 time=7.61 ms
64 bytes from 199.7.83.42: icmp_seq=3 ttl=56 time=7.87 ms
64 bytes from 199.7.83.42: icmp_seq=4 ttl=56 time=7.21 ms
64 bytes from 199.7.83.42: icmp_seq=5 ttl=56 time=7.88 ms
---
l.root-servers.net ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4006ms
rtt min/avg/max/mdev = 7.212/8.247/10.667/1.233 ms
根服务器在上海?