Robtex

Up: 216.21.0.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 216.21.0.0/22
Down right: 216.21.4.0/22

IP	Type	Hostname
216.21.2.1	A+PTR	itrouter.sjc.pch.net
216.21.2.2	PTR	itswitch.sjc.pch.net
216.21.2.5	A+PTR	vm1-it-lom.sjc.woodynet.net
216.21.2.6	A+PTR	vm1-it.sjc.woodynet.net
216.21.2.212	A	rcom-test-whois.tv
216.21.3.41	A	admin1.sjc.rrdns.pch.net
216.21.3.54	A	web1.sjc.rrdns.pch.net
216.21.3.73	A	proxy3.sjc.rrdns.pch.net
216.21.3.77	A	www.quad9.net
216.21.3.77	A	quad9.net
216.21.3.77	A	www.quad9.com
216.21.3.84	A	mx2.quad9.net
216.21.3.194	A	inbound4.loligo.com
216.21.3.196	A	www.loligo.com
216.21.7.8	A	mail.terrafirmacommunications.net
216.21.7.8	A	mail.terrafirmaconferencing.com