Robtex

Up: 208.84.66.0/24
Can't show all results, try to descend to a more specific CIDR
Down left: 208.84.66.128/26
Down right: 208.84.66.192/26
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
208.84.66.128	A	spf-mailers.proofpoint.com
208.84.66.164	A+PTR	ingest.pulse.proofpoint.com
208.84.66.193	A+PTR	support1.proofpoint.com
208.84.66.193	A	spf-mailers.proofpoint.com
208.84.66.193	A	support-sc4.proofpoint.com
208.84.66.194	A+PTR	mbay5.mx.proofpoint.com
208.84.66.195	A+PTR	prs-sc4.proofpoint.com
208.84.66.195	A	prs.gslb.proofpoint.com
208.84.66.195	A	prsns2.proofpoint.com
208.84.66.196	PTR	update-sc4.proofpoint.com
208.84.66.196	A	v3.update.proofpoint.com
208.84.66.196	A	update2.proofpoint.com
208.84.66.197	A+PTR	pdus-sc4.proofpoint.com
208.84.66.197	A	pdus.proofpoint.com
208.84.66.198	A+PTR	ntp-sc4.proofpoint.com
208.84.66.200	A+PTR	dl1.proofpoint.com
208.84.66.200	A	dl1-sc4.proofpoint.com
208.84.66.201	A+PTR	f-secure.proofpoint.com
208.84.66.201	A	f-secure-sc4.proofpoint.com
208.84.66.203	A+PTR	mbay3.mx.proofpoint.com
208.84.66.204	A+PTR	mbay4.mx.proofpoint.com
208.84.66.204	A	mbay7.mx.proofpoint.com
208.84.66.205	A+PTR	mbay1.mx.proofpoint.com
208.84.66.206	A	update-test-sc4.proofpoint.com
208.84.66.207	PTR	help.tryproofpoint.com
208.84.66.207	A	help-sc4.tryproofpoint.com
208.84.66.208	PTR	ns1-sc4.proofpoint.com
208.84.66.208	PTR	ns3.proofpoint.com
208.84.66.208	A+PTR	ns2.proofpoint.com
208.84.66.209	A+PTR	zerohour2.proofpoint.com
208.84.66.209	A	zerohour.proofpoint.com
208.84.66.210	A	mx3001.piscesdns.net
208.84.66.210	A	208-84-66-214.proofpoint.com
208.84.66.211	A	download.tryproofpoint.com
208.84.66.212	A+PTR	hks-sc4.proofpoint.com
208.84.66.212	A	pphks.gslb.pphosted.com
208.84.66.213	A	mail.cisolutions.ru
208.84.66.213	A	troll.worldkey.net
208.84.66.213	A	worldkey.worldkey.net
208.84.66.214	A	mx3003.piscesdns.net
208.84.66.214	A	wa2.so-ne.ne.jp
208.84.66.215	A+PTR	pdus-test-sc4.proofpoint.com
208.84.66.217	A+PTR	*.datadiscover.proofpoint.com
208.84.66.217	A	txlifeinsurancecompany.datadiscover.proofpoint.com
208.84.66.218	A+PTR	trafficcontrol.proofpoint.com
208.84.66.219	A	*.gregpub.com
208.84.66.219	A	mx3004.piscesdns.net
208.84.66.219	A	mx3.gregpub.com
208.84.66.221	A+PTR	inventory.proofpoint.com
208.84.66.222	A+PTR	prscollect.proofpoint.com
208.84.66.222	A	prscollect-sc4.proofpoint.com
208.84.66.223	A+PTR	fts-01.pphosted.com
208.84.66.223	A+PTR	hft-us.pphosted.com
208.84.66.223	A+PTR	spf-mailers.proofpoint.com
208.84.66.224	PTR	ccstest.proofpoint.com
208.84.66.224	A	ccs.proofpoint.com
208.84.66.224	A	ccs-sc4.proofpoint.com
208.84.66.225	A	mx3005.piscesdns.net
208.84.66.225	A	supportebay.com
208.84.66.226	PTR	208-84-66-226.proofpoint.com
208.84.66.226	A	*.panamnet.net
208.84.66.226	A	ns1.joefuzz.com
208.84.66.227	PTR	208-84-66-227.proofpoint.com
208.84.66.227	A	*.princessvagina.com
208.84.66.227	A	hostmaster.ndnet.net
208.84.66.228	A	mx3008.piscesdns.net
208.84.66.228	A	208-84-66-228.proofpoint.com
208.84.66.230	PTR	zombiewatchtest.proofpoint.com
208.84.66.230	A	zombiewatch.proofpoint.com
208.84.66.231	PTR	arcdatatest.proofpoint.com
208.84.66.231	A+PTR	arcdata.proofpoint.com
208.84.66.240	A	cts3-api.proofpoint.com
208.84.66.241	A	cts1.proofpoint.com
208.84.66.242	A+PTR	cts2.proofpoint.com
208.84.66.243	A	cts3.proofpoint.com
208.84.66.244	A	cts4.proofpoint.com
208.84.66.247	A	cts3-updates.proofpoint.com
208.84.66.248	PTR	chat.proofpoint.com
208.84.66.249	A+PTR	*.socialsandbox.proofpoint.com
208.84.66.249	A	lcs.proofpoint.com
208.84.66.250	A+PTR	kb.proofpoint.com