shell:$ nslookup -timeout=2 -retry=1 'isitupdown.com'
Server:		1.1.1.1
Address:	1.1.1.1#53

Non-authoritative answer:
Name:	isitupdown.com
Address: 104.21.89.237
Name:	isitupdown.com
Address: 172.67.191.236
Name:	isitupdown.com
Address: 2606:4700:3031::ac43:bfec
Name:	isitupdown.com
Address: 2606:4700:3030::6815:59ed