Get DNS name from IP

To get the DNS name from the IP just use nslookup :)
E.g.

kim@X151023:~$ ping google.com
PING google.com (64.233.187.99) 56(84) bytes of data.
64 bytes from jc-in-f99.google.com (64.233.187.99): icmp_seq=1 ttl=239 time=116 ms

--- google.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 1999ms
rtt min/avg/max/mdev = 111.008/113.074/116.091/2.215 ms
kim@X151023:~$ nslookup 64.233.187.99
Server:  10.17.3.7
Address: 10.17.3.7#53

Non-authoritative answer:
99.187.233.64.in-addr.arpa name = jc-in-f99.google.com.

Authoritative answers can be found from:

kim@X151023:~$