次のコマンドは両方ともOKです!
208.97.177.124 => apache2-argon.william-floyd.dreamhost.com
nslookup -type=PTR 208.97.177.124 in-addr.arpa
nslookup -type=PTR 208.97.177.124
nslookup 208.97.177.124
しかし、このコマンドは正しくありません!
208.97.177.124 => CPE-124-177-97-208.lns6.cha.bigpond.net.au
nslookup -type=PTR 208.97.177.124.in-addr.arpa
Microsoft Windows [Version 10.0.14393]
(c) 2016 Microsoft Corporation. All rights reserved.
G:\JavaScript Testing>nslookup -type=PTR 208.97.177.124.in-addr.arpa
Server: phicomm.me
Address: 192.168.2.1
Non-authoritative answer:
208.97.177.124.in-addr.arpa name = CPE-124-177-97-208.lns6.cha.bigpond.net.au
G:\JavaScript Testing>nslookup -type=PTR 208.97.177.124
Server: phicomm.me
Address: 192.168.2.1
Non-authoritative answer:
124.177.97.208.in-addr.arpa name = apache2-argon.william-floyd.dreamhost.com
G:\JavaScript Testing>nslookup -type=PTR 208.97.177.124 in-addr.arpa
*** Can't find server address for 'in-addr.arpa':
Server: phicomm.me
Address: 192.168.2.1
Non-authoritative answer:
124.177.97.208.in-addr.arpa name = apache2-argon.william-floyd.dreamhost.com
G:\JavaScript Testing>
参照リンク:
https://ist.mit.edu/network/ip