Robtex

Up: 166.77.10.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 166.77.11.0/25
Down right: 166.77.11.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
166.77.11.7	A	mail03.viacom.com
166.77.11.9	A	mail05.viacom.com
166.77.11.10	A+PTR	mail06.viacom.com
166.77.11.22	A	owa.comedycentral.com
166.77.11.24	A	mailrelay5.viacom.com
166.77.11.25	A	mailrelay6.viacom.com
166.77.11.26	A	mail01.viacom.com
166.77.11.27	A	mail01.mtv.com
166.77.11.28	A+PTR	mail01.vh1.com
166.77.11.29	A	mailout01.viacom.com
166.77.11.30	A	mail01a.viacom.com
166.77.11.31	A	mail02a.viacom.com
166.77.11.32	A+PTR	mail03.vh1.com
166.77.11.33	A+PTR	mail03.mtv.com
166.77.11.34	A	mail03a.viacom.com
166.77.11.35	A+PTR	mailout03.viacom.com
166.77.11.36	A+PTR	mail02.viacom.com
166.77.11.37	A	mail02.mtv.com
166.77.11.38	A+PTR	mail02.vh1.com
166.77.11.39	A+PTR	mailout02.viacom.com
166.77.11.40	A	mail04.mtv-asia.com
166.77.11.45	A+PTR	maila.viacom.com
166.77.11.46	A+PTR	mail.viacom.com
166.77.11.47	A+PTR	mail.mtv.com
166.77.11.48	PTR	mail.vh1.com
166.77.11.48	A	mail.mtv-asia.com
166.77.11.49	A+PTR	mailout.viacom.com
166.77.11.50	A+PTR	mail1.viacom.com
166.77.11.51	PTR	ecomrelay4.viacom.com
166.77.11.51	A	mail1.mtv-asia.com
166.77.11.52	A+PTR	mail1.mtv.com
166.77.11.60	PTR	lcs.viacom.com
166.77.11.68	A+PTR	smtp-mail.mtvne.com
166.77.11.69	A	ipmailrelay.viacom.com
166.77.11.78	PTR	mta1.neopetsinc.com
166.77.11.78	A	mta1.neopetsfoundation.org
166.77.11.78	A	mta3.teen-offers.com
166.77.11.81	A	lcs.viacom.com
166.77.11.116	A	thespotaway.viacom.com
166.77.11.119	A	adspecs.mtvn.com
166.77.11.150	A	chat.viacom.com
166.77.11.170	A	spikeintranet.com
166.77.11.170	A	comedyintranet.com
166.77.11.170	A	cmtintranet.com
166.77.11.178	A	mail.bellator.com
166.77.11.184	A+PTR	maile.bet.net
166.77.11.221	A	lyncwebext.viacom.com
166.77.11.221	A	lync.viacom.com