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

Non-authoritative answer:
mqtt-mini.facebook.com	canonical name = mqtt-mini.c10r.facebook.com.
Name:	mqtt-mini.c10r.facebook.com
Address: 57.144.172.9
Name:	mqtt-mini.c10r.facebook.com
Address: 2a03:2880:f356:9:face:b00c:0:1ea0