Robtex

Up: 206.46.160.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 206.46.164.0/23
Down right: 206.46.166.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
206.46.164.1	PTR	mta1.bizmailsrvcs.net
206.46.164.3	PTR	web1.bizmailsrvcs.net
206.46.164.4	A	imap.centerstatebank.com
206.46.164.22	PTR	oe-mp1pub.managedmail.com
206.46.164.22	A	naindust.com
206.46.164.22	A	mx1.edcspin.usinternet.com
206.46.164.23	PTR	oe-mp2pub.managedmail.com
206.46.164.24	PTR	oe-ismta1pub.managedmail.com
206.46.164.25	PTR	oe-ismta2pub.managedmail.com
206.46.164.27	A+PTR	oe-iscan2pub.managedmail.com
206.46.164.29	A+PTR	mm-iscan2pub.managedmail.com
206.46.164.32	A	oe-iw1pub.managedmail.com
206.46.164.33	A+PTR	oe-iw2pub.managedmail.com
206.46.165.12	PTR	dnecw1.vzlink.com
206.46.165.12	A	cw.vzlink.com
206.46.165.254	A	offline-gw.gte.net
206.46.166.11	A+PTR	survey.gte.net
206.46.166.23	A+PTR	tock.west.verizon.net