shell:$ nslookup -timeout=2 -retry=1 'whois.markmonitor.com'
Server:		75.98.161.224
Address:	75.98.161.224#53

Non-authoritative answer:
whois.markmonitor.com	canonical name = whois.aws.markmonitor.com.
Name:	whois.aws.markmonitor.com
Address: 35.84.53.85
Name:	whois.aws.markmonitor.com
Address: 54.184.27.190
Name:	whois.aws.markmonitor.com
Address: 35.167.139.47