Robtex

Up: 204.15.200.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 204.15.204.0/23
Down right: 204.15.206.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
204.15.204.67	A+PTR	mx1.htcplus.net
204.15.204.67	A	mx1.htcplus.com
204.15.204.67	A	mx.htcplus.net
204.15.204.68	A+PTR	mx2.htcplus.com
204.15.204.70	A	mx4.htcplus.com
204.15.204.70	A	mx4.htcplus.net
204.15.204.71	A	mx5.htcplus.com
204.15.204.73	A	ns1.towncable.com
204.15.204.73	A	ns1.traditiontv.tv
204.15.204.73	A	ns1.tesorotv.com
204.15.204.74	A	ns1.myhtcplus.net
204.15.204.80	A+PTR	mail.htcplus.net
204.15.204.81	A	www.htcplus.net
204.15.204.81	A	htcplus.net
204.15.204.82	A	traditiontv.com
204.15.204.105	A	webmail.htcplus.com
204.15.204.106	A+PTR	extftp.htcplus.com
204.15.204.138	PTR	cs201.po1.htcplus.com
204.15.204.138	A	occ-0-3611-3934.1.nflxso.net
204.15.204.138	A	occ-0-3611-3933.1.nflxso.net
204.15.204.254	PTR	br101.fa0-1.htcplus.com
204.15.205.35	A+PTR	mail.hollywoodmedia.com
204.15.205.36	PTR	204-15-205-36.port-st-lucie.fl.bluestreamfiber.net
204.15.205.36	A	ns1.hollywoodmedia.com
204.15.205.36	A	dns.hollywoodmedia.com
204.15.205.82	A	mail.whaclaws.com
204.15.206.3	PTR	sr301.e0.htcplus.com
204.15.207.4	A	ns1.hometowntelephone.net
204.15.207.5	A+PTR	ns2.hometowntelephone.net
204.15.207.22	A+PTR	hometowntelephone.net
204.15.207.22	A+PTR	www.hometowntelephone.net
204.15.207.27	A+PTR	graycom.net
204.15.207.27	PTR	fastlink.graycom.net
204.15.207.27	PTR	ftp.graycom.net
204.15.207.28	A	httjm.com
204.15.207.29	A	mail.httjm.com
204.15.207.34	A+PTR	avarena.org
204.15.207.34	A+PTR	avarenadb.avarena.tv
204.15.207.36	PTR	vdrv.com
204.15.207.74	A	catiroy.com
204.15.207.76	PTR	thevideofone
204.15.207.76	A+PTR	thevideofone.com
204.15.207.99	A+PTR	listener1.avarena.tv
204.15.207.99	A+PTR	staging.avarena.tv
204.15.207.99	A+PTR	videolibrarydb.avarena.tv
204.15.207.110	A+PTR	avarena.tv
204.15.207.174	A	safescrew.com
204.15.207.225	A	mail.avarena.org