nslookup按一按會很難麼..
> 163.21.39.20
Server: dns.hinet.net
Address: 168.95.1.1

39.21.163.in-addr.arpa nameserver = tpws129.mcjh.tp.edu.tw
tpws129.mcjh.tp.edu.tw internet address = 163.21.39.2
*** No address (A) records available for 163.21.39.20