$ dig +nocmd +noall +answer a google.com
google.com. 300 IN A 74.125.239.37
google.com. 300 IN A 74.125.239.33
google.com. 300 IN A 74.125.239.34

Run it again..

$ dig +nocmd +noall +answer a google.com
google.com. 288 IN A 74.125.239.33
google.com. 288 IN A 74.125.239.34
google.com. 288 IN A 74.125.239.39