How to find the all the ip adddress for one domain name

Busy sites, such as cnn.com, are replicated over multiple servers, with each server running on a different end system and each having a different IP address. 

For replicated Web servers, a set of IP addresses is thus associated with one canonical hostname.

In this session shows how to find the all the ip address for one canonical host name in the linux os

As a example try to find the all the ip address for www.google.com, it's mean replicated servers for www.google.com

first we have to find the one ip address for www.google.com (using ping cammand)
 
$ ping www.google.com
PING www.google.com (194.90.196.121) 56(84) bytes of data.
64 bytes from 194.90.196.121: icmp_seq=1 ttl=128 time=256 ms
64 bytes from 194.90.196.121: icmp_seq=2 ttl=128 time=224 ms
64 bytes from 194.90.196.121: icmp_seq=3 ttl=128 time=252 ms
64 bytes from 194.90.196.121: icmp_seq=4 ttl=128 time=259 ms
64 bytes from 194.90.196.121: icmp_seq=5 ttl=128 time=226 ms


after that using whois command to find the origin 

whois -h whois.radb.net  194.90.196.121
 

after that type this command to find the all the ip address using origin AS1680
whois -h whois.radb.net '!gAS1680'