Robtex

Up: 64.8.70.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 64.8.71.0/25
Down right: 64.8.71.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
64.8.71.5	PTR	uat.my.synacor.com
64.8.71.5	PTR	uat.synapps.synacor.com
64.8.71.10	A+PTR	tarpit.synacor.com
64.8.71.14	A+PTR	smtpout.cincibell.syn-alias.com
64.8.71.14	A	mail.citecorp.net
64.8.71.14	A	mail.bloomington.in.us
64.8.71.15	PTR	mx.fuse.net
64.8.71.15	A	mx2.fusenet.com
64.8.71.15	A	mx2.fuse.com
64.8.71.16	PTR	pop.fuse.net
64.8.71.16	A	imap.fuse.net
64.8.71.16	A	pop3.fuse.net
64.8.71.19	A+PTR	smtpout-fo.fuse.net
64.8.71.22	A+PTR	mailrelay.armstrong.synacor.com
64.8.71.22	A	smtp.zoominternet.syn-alias.com
64.8.71.23	PTR	mx.armstrong.synacor.com
64.8.71.23	A	smtp-abroad.zoominternet.net
64.8.71.23	A	mail.ncrvfc.com
64.8.71.24	A+PTR	mailrelay-fo.armstrong.synacor.com
64.8.71.25	A+PTR	secure.hawaiiantel.net.portal.syn-alias.com
64.8.71.43	A	login.wildblue.net
64.8.71.43	A	login.wildblue.net.portal.syn-alias.com
64.8.71.58	A	login.directv.net.portal.syn-alias.com
64.8.71.70	PTR	content.uat03.garnet.synacor.com
64.8.71.70	A	authorize.myhughesnet.com.ent.syn-alias.com
64.8.71.70	A	authorize.myhughesnet.com
64.8.71.72	A	identity.sling.com
64.8.71.72	A	identity.sling.com.ent.syn-alias.com
64.8.71.100	A	webmail.mlb.com
64.8.71.106	A	imap.zoominternet.net
64.8.71.106	A	mail.zoominternet.syn-alias.com
64.8.71.111	A+PTR	mx.wowway.com
64.8.71.111	A	mx.knology.net
64.8.71.112	A+PTR	smtp.knology.net
64.8.71.112	A	mail.wowwaynet.syn-alias.com
64.8.71.112	A	mail.knology.syn-alias.com
64.8.71.113	A+PTR	smtp.iw.net
64.8.71.113	A	pop3.iw.net
64.8.71.114	PTR	smtp.rushmore.com
64.8.71.114	A	mail.rushmore.syn-alias.com
64.8.71.114	A	mail.rushmore.com
64.8.71.115	A+PTR	smtp.sunflower.com
64.8.71.116	A+PTR	smtp.graceba.net
64.8.71.116	A	pop.graceba.net
64.8.71.116	A	pop.snowhill.com
64.8.71.117	A+PTR	mail.pclnet.net
64.8.71.118	A+PTR	smtp-fo.knology.synacor.com
64.8.71.119	PTR	mail.wowway.synacor.com
64.8.71.119	A	mail.wowway.syn-alias.com
64.8.71.119	A	pop3.mail.wowway.com
64.8.71.143	PTR	static.uat21.diamond.synacor.com
64.8.71.147	A+PTR	web.uat04.garnet.synacor.com
64.8.71.230	A+PTR	secure-my.wavebroadband.com.portal.syn-alias.com
64.8.71.230	A	secure-my.wavebroadband.com
64.8.71.236	A	demo.synacor.com
64.8.71.237	A	static.sapphire.synacor.com