shell:$ nslookup -timeout=2 -retry=1 '5481512.fls.doubleclick.net'
Server:		1.1.1.1
Address:	1.1.1.1#53

Non-authoritative answer:
5481512.fls.doubleclick.net	canonical name = dart.l.doubleclick.net.
Name:	dart.l.doubleclick.net
Address: 172.253.132.149
Name:	dart.l.doubleclick.net
Address: 172.253.132.148