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

Non-authoritative answer:
pixel.rubiconproject.com	canonical name = pixel.rubiconproject.net.akadns.net.
Name:	pixel.rubiconproject.net.akadns.net
Address: 69.173.146.5