Robtex

Up: 66.187.224.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 66.187.232.0/22
Down right: 66.187.236.0/22
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
66.187.232.10	PTR	unused
66.187.232.16	PTR	unused
66.187.232.20	A	us-east.sip.akadns.net
66.187.232.20	A	sipx-sbc03.geo.redhat.com
66.187.232.50	PTR	unused
66.187.232.50	A	labs.redhat.com
66.187.232.50	A	rhl.redhat.com
66.187.232.59	PTR	unused
66.187.232.64	A+PTR	ovpn-rdu2.redhat.com
66.187.232.72	PTR	unused
66.187.232.74	PTR	unused
66.187.232.88	PTR	unused
66.187.232.120	PTR	reserved
66.187.232.132	A	queue.rhn.redhat.com
66.187.232.134	A	mail.rhn.redhat.com
66.187.232.192	PTR	unused
66.187.232.201	PTR	unused
66.187.232.232	PTR	unused
66.187.232.249	PTR	unused
66.187.233.4	A	clock1.redhat.com
66.187.233.27	A	ns1-rdu.redhat.com
66.187.233.28	A+PTR	ns2-rdu.redhat.com
66.187.233.29	A	ns3-rdu.redhat.com
66.187.233.31	A	mx1-old.redhat.com
66.187.233.32	PTR	mx02-util-rdu2.redhat.com
66.187.233.32	A	mx3.redhat.com
66.187.233.32	A	mx3.fedoraproject.org
66.187.233.33	PTR	mx2.redhat.com
66.187.233.34	PTR	mx2.redhat.com
66.187.233.53	PTR	reserved
66.187.233.71	A	mx2.redhat.com
66.187.233.89	PTR	ip-66-187-233-89.redhat.com
66.187.233.89	A	webvpn.redhat.com
66.187.233.96	PTR	nat-reserved
66.187.233.97	PTR	nat-reserved
66.187.233.200	A+PTR	nat-pool-rdu.redhat.com
66.187.233.201	A	wireless-nat-pool-rdu.redhat.com
66.187.233.202	PTR	nat-pool-rdu-t.redhat.com
66.187.233.202	A	jaddog.org
66.187.233.202	A	mail.aliceradez.org
66.187.233.203	PTR	nat-pool-rdu-u.redhat.com
66.187.233.210	PTR	nat-reserved
66.187.233.212	A+PTR	ns3.redhat.com
66.187.233.213	A	ns3.geo.redhat.com
66.187.233.221	A	sebastian.redhat.com
66.187.233.222	A	ovpn-rdu2-contractor.redhat.com
66.187.233.240	PTR	ip-66-187-233-240.redhat.com
66.187.233.240	A	aurora.redhat.com
66.187.233.244	A	mayberry.redhat.com
66.187.233.249	PTR	reserved
66.187.233.249	A	router-i2.redhat.com
66.187.233.254	A	router.redhat.com
66.187.234.80	PTR	ip-80-234-187-66.redhat.com
66.187.234.147	PTR	ip-147-234-187-66.redhat.com
66.187.237.10	A	nat-pool-tlv-t1.redhat.com
66.187.237.11	A	nat-pool-tlv-u1.redhat.com
66.187.237.31	A	mx2.fedoraproject.org
66.187.237.50	PTR	unused
66.187.237.162	PTR	unused
66.187.237.248	PTR	unused
66.187.237.252	A	vpn-tlv.redhat.com
66.187.238.130	PTR	unused
66.187.238.163	PTR	unused
66.187.238.219	PTR	unused
66.187.239.91	PTR	unused
66.187.239.98	PTR	unused
66.187.239.193	PTR	unused
66.187.239.201	A	nat-pool-bne.redhat.com
66.187.239.226	PTR	unused
66.187.239.254	A	fw01-bne.redhat.com