Robtex

Up: 64.136.40.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 64.136.44.0/23
Down right: 64.136.46.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
64.136.44.11	A+PTR	dns-mail01.dca.untd.com
64.136.44.12	A+PTR	dns-mail02.dca.untd.com
64.136.44.17	A+PTR	feed.dca.untd.com
64.136.44.17	A	feed.untd.com
64.136.44.18	A+PTR	cyclops.dca.untd.com
64.136.44.18	A	cyclops.prod.untd.com
64.136.44.21	PTR	nztv.dca.untd.com
64.136.44.21	A	nztv.juno.com
64.136.44.21	A	nztv.netzero.net
64.136.44.22	PTR	vas-ui.dca.untd.com
64.136.44.25	A+PTR	phoenix.dca.untd.com
64.136.44.25	A	phoenixcm.untd.com
64.136.44.25	A	phoenix.untd.com
64.136.44.28	A+PTR	phoenix4.dca.untd.com
64.136.44.29	A+PTR	phoenix5.dca.untd.com
64.136.44.33	A+PTR	zm.dca.untd.com
64.136.44.33	A	zm.netzero.net
64.136.44.34	A+PTR	pop.dca.netzero.net
64.136.44.34	A	pop.netzero.net
64.136.44.35	PTR	pop.dca.juno.com
64.136.44.36	A	pop.mybluelight.com
64.136.44.37	PTR	mx.dca.untd.com
64.136.44.37	A	mx-ws.namethattuna.net
64.136.44.37	A	mx-fol.dca.untd.com
64.136.44.38	PTR	mxcorp.dca.untd.com
64.136.44.40	A+PTR	smtp.dca.emailmyname.com
64.136.44.40	A	smtp.mybluelight.com
64.136.44.40	A	smtp.emailmyname.com
64.136.44.42	PTR	mp.dca.untd.com
64.136.44.43	PTR	rd.dca.ads.juno.com
64.136.44.44	A+PTR	smtp.dca.netzero.net
64.136.44.44	A	authsmtp.netzero.net
64.136.44.44	A	smtp.netzero.net
64.136.44.45	PTR	smtp.dca.juno.com
64.136.44.45	A	smtp.juno.com
64.136.44.47	PTR	umap.dca.juno.com
64.136.44.48	A+PTR	pop.dca.netzero.com
64.136.44.48	A	pop.netzero.com
64.136.44.48	A	pop-com.netzero.net
64.136.44.49	PTR	content.dca.untd.com
64.136.44.49	A	content.untd.com
64.136.44.50	PTR	smtp.dca.netzero.com
64.136.44.53	A	m03.nyc.untd.com
64.136.44.55	A+PTR	m05.nyc.untd.com
64.136.44.57	A	m07.nyc.untd.com
64.136.44.65	A	ap.dca.netzero.net
64.136.44.66	A	apserv.dca.untd.com
64.136.44.67	A+PTR	rtserv.dca.untd.com
64.136.44.71	A+PTR	searchap.dca.untd.com
64.136.44.72	A+PTR	cdrestrict-dns.dca.untd.com
64.136.44.73	PTR	vgs-dns.dca.untd.com
64.136.44.73	A	lax-dns.dca.untd.com
64.136.44.75	A+PTR	minidns.dca.mini.untd.com
64.136.44.79	A	ccfail-dns.dca.untd.com
64.136.44.80	A+PTR	resetpw-dns.dca.untd.com
64.136.44.81	A+PTR	qsdownload-dns.dca.untd.com
64.136.44.83	A+PTR	maclock-dns.dca.untd.com
64.136.44.85	A	z3warn-dns2.dca.untd.com
64.136.44.89	A+PTR	resetpw-dns2.dca.untd.com
64.136.44.90	A+PTR	qsdownload-dns2.dca.untd.com
64.136.44.92	PTR	auth-vip1.dca.untd.com
64.136.44.93	A	auth-vip2.dca.untd.com
64.136.44.95	A+PTR	msirs-dns2.dca.untd.com
64.136.44.97	A+PTR	profile-dns.dca.untd.com
64.136.44.99	PTR	vgs-dns2.dca.untd.com
64.136.44.102	A+PTR	message-dns.dca.untd.com
64.136.44.103	A+PTR	restrict-dns.dca.untd.com
64.136.44.104	A+PTR	bb-dca-dns.dca.untd.com
64.136.44.105	A+PTR	bb-vgs-dns.dca.untd.com
64.136.44.106	A+PTR	nose-dca-dns.dca.untd.com
64.136.44.107	A+PTR	nose-vgs-dns.dca.untd.com
64.136.44.108	A+PTR	radius-cisp.dca.untd.com
64.136.44.109	A	radius-ynp.dca.untd.com
64.136.44.111	A+PTR	message-dns.dca.mini.untd.com
64.136.44.112	A+PTR	restrict-dns.dca.mini.untd.com
64.136.44.113	A+PTR	cdrestrict-dns.dca.mini.untd.com
64.136.44.114	A	lax-dns.dca.atg.untd.com
64.136.44.115	PTR	authns2.untd.com
64.136.44.115	A	authns2.emailmyname.com
64.136.44.116	PTR	authns-ws.dca.mysite.com
64.136.44.118	A+PTR	authns.dca.emailmyname.com
64.136.44.118	A	authns2.emailmyname.com
64.136.44.118	A	authns.nyc.mysite.com
64.136.44.123	PTR	ns2.freeservers.com
64.136.44.123	A	ns2.global-servers.com
64.136.44.123	A	ns2.50megs.com
64.136.44.124	A+PTR	ns4.freeservers.com
64.136.44.126	A+PTR	wl-dns.dca.untd.com
64.136.45.22	A+PTR	dl.dca.netzero.net
64.136.45.22	A	dl.netzero.net
64.136.45.25	A+PTR	accountb.dca.juno.com
64.136.45.25	A	accountb.juno.com
64.136.45.26	PTR	accountb.dca.netzero.net
64.136.45.26	A	accountb.netzero.net
64.136.45.27	PTR	accountb.dca.mybluelight.com
64.136.45.27	A	accountb.mybluelight.com
64.136.45.28	A	register.netzero.net
64.136.45.29	A	register.dca.juno.com
64.136.45.30	A+PTR	track.dca.untd.com
64.136.45.30	A	track.untd.com
64.136.45.31	PTR	track.dca.netzero.net
64.136.45.32	A+PTR	track.dca.juno.com
64.136.45.32	A	track.juno.com
64.136.45.34	A+PTR	track.dca.mysite.com
64.136.45.37	A+PTR	accountb.dca.untd.com
64.136.45.37	A	accountb.untd.com
64.136.45.38	PTR	search.dca.untd.com
64.136.45.38	A	endphonespam.biz
64.136.45.38	A	nzplatinum.com
64.136.45.39	PTR	my.dca.netzero.com
64.136.45.41	A	my-message.dca.untd.com
64.136.45.43	PTR	www.dca.mybluelight.com
64.136.45.43	A	www.bluelightsurfspeed.com
64.136.45.43	A	bluelightaccess.com
64.136.45.44	PTR	start.dca.mybluelight.com
64.136.45.44	A	mobile-mybluelight.com
64.136.45.44	A	startbluelight.com
64.136.45.46	PTR	my.dca.juno.com
64.136.45.46	A	mobile-juno.com
64.136.45.48	A+PTR	my-z3lock.dca.juno.com
64.136.45.49	A	my-eap.dca.juno.com
64.136.45.59	A+PTR	webmail.dca.mybluelight.com
64.136.45.59	A	webmail.mybluelight.com
64.136.45.64	PTR	vanity.dca.mysite.com
64.136.45.64	A	www.king.us
64.136.45.64	A	cross.us
64.136.45.66	PTR	webmail.dca.mysite.com
64.136.45.68	A+PTR	account.dca.juno.com
64.136.45.68	A	account.juno.com
64.136.45.69	PTR	account.dca.netzero.net
64.136.45.69	A	freei.net
64.136.45.69	A	account.netzero.net
64.136.45.71	PTR	my.dca.netzero.net
64.136.45.80	A+PTR	my-msirs.dca.untd.com
64.136.45.81	A+PTR	account.dca.netzero.com
64.136.45.81	A	account.netzero.com
64.136.45.83	PTR	webmail.dca.netzero.net
64.136.45.83	A	webmail.netzero.com
64.136.45.84	A+PTR	webmail.dca.juno.com
64.136.45.84	A	webmail.juno.com
64.136.45.84	A	webmailb.juno.com
64.136.45.86	A	verify.netzerovoice.com
64.136.45.93	A	my-message.dca.netzero.net
64.136.45.99	A	my-cdrestrict.dca.juno.com
64.136.45.102	A+PTR	redirect.account.dca.juno.com
64.136.45.104	A	redirect.www.juno.com
64.136.45.104	A	www.junowireless.com
64.136.45.106	A	legal-redirect.www.dca.juno.com
64.136.45.113	PTR	dl.www.dca.juno.com
64.136.45.113	A	dl.www.juno.com
64.136.45.114	A+PTR	dl2.www.dca.juno.com
64.136.45.114	A	dl2.www.juno.com
64.136.45.116	A+PTR	ordercd.dca.netzero.net
64.136.45.116	A	ordercd.netzero.net
64.136.45.151	PTR	www.dca.netzeromarketing.com
64.136.45.151	A	www.netzeromarketing.com
64.136.45.159	PTR	umap.dca.juno.com
64.136.45.160	PTR	www.photosite.com
64.136.45.168	PTR	www.dca.netzero.net
64.136.45.168	A	www.netzero.net
64.136.45.168	A	netzero.net
64.136.45.169	PTR	www.dca.juno.com
64.136.45.178	PTR	store.dca.juno.com
64.136.45.178	A	store.juno.com
64.136.45.179	PTR	store.dca.netzero.net
64.136.45.179	A	store.netzero.net
64.136.45.183	A+PTR	phonereg.dca.untd.com
64.136.45.184	A+PTR	webmailbb.juno.com
64.136.45.185	A+PTR	webmailbb.netzero.net
64.136.45.185	A	webmailbb.uolstatic.com
64.136.45.185	A	webmailbb.uolimg.com
64.136.45.188	A+PTR	vpmdb.netzero.net
64.136.45.189	A+PTR	vpmdbb.netzero.net
64.136.45.190	A+PTR	vpmdb.juno.com
64.136.45.191	A+PTR	vpmdbb.juno.com
64.136.45.192	A	vpmd-httpb.netzero.net
64.136.45.193	A	vpmd-httpbb.netzero.net
64.136.45.194	A+PTR	vpmd-httpb.juno.com
64.136.45.195	A	vpmd-httpbb.juno.com
64.136.45.212	A+PTR	help.dca.juno.com
64.136.45.212	A	help.juno.com
64.136.45.213	PTR	help.dca.netzero.net
64.136.45.213	A	help.netzero.net
64.136.45.215	PTR	tagline.dca.juno.com
64.136.45.215	A	thirdpartyoffers.juno.com
64.136.45.216	PTR	tagline.dca.netzero.net
64.136.45.216	A	tagline.netzero.net
64.136.45.219	PTR	captcha.dca.uolimg.com
64.136.45.219	A	captcha.uolimg.com
64.136.45.220	PTR	www.dca.untd.com
64.136.45.220	A	leyjekowsma.freehosting.net
64.136.45.220	A	www.nuticnijes.freehosting.net
64.136.45.221	PTR	postmaster.dca.untd.com
64.136.47.10	PTR	outbound-bu0.dca.untd.com
64.136.47.16	A+PTR	outbound-mx.dca.untd.com
64.136.47.17	A	outbound-mailuser01.dca.untd.com
64.136.47.28	A+PTR	logs-mx.dca.office.untd.com
64.136.47.28	A	staff.juno.com
64.136.47.28	A	world.juno.com
64.136.47.29	A+PTR	mx.dca.office.untd.com
64.136.47.36	A+PTR	outbound-mail02.dca.untd.com
64.136.47.37	A+PTR	outbound-mail03.dca.untd.com
64.136.47.50	PTR	blue.dca.untd.com
64.136.47.50	A	mailtransfer.dca.untd.com
64.136.47.56	A+PTR	dns-resolv02.dca.untd.com
64.136.47.62	A+PTR	blaze2.dca.untd.com