Robtex

Up: 66.218.72.0/22
Can't show all results, try to descend to a more specific CIDR
Down left: 66.218.74.0/24
Down right: 66.218.75.0/24
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
66.218.74.1	A	ha1.vl-127.bas-6-prd.bf1.yahoo.com
66.218.74.63	A	vcs-star-im-yc.mail.vip.bf1.yahoo.com
66.218.74.79	A+PTR	web141216.mail.bf1.yahoo.com
66.218.74.119	A+PTR	partners.news.yahoo.com
66.218.74.148	PTR	unknown.yahoo.com
66.218.74.148	A	htc.imap.mail.yahoo.com
66.218.74.148	A	imap.mail.am0.yahoodns.net
66.218.74.149	PTR	unknown.yahoo.com
66.218.74.151	PTR	unknown.yahoo.com
66.218.74.151	A	pop-att.mail.yahoo.com
66.218.74.154	PTR	mg1001.mail.vip.bf1.yahoo.com
66.218.74.154	A	leizel.mg.mail.yahoo.com
66.218.74.154	A	global.mg.mail.gm0.yahoodns.net
66.218.74.156	PTR	unknown-66-218-74-x.yahoo.com
66.218.74.156	A	pop.mail.sbc.am0.yahoodns.net
66.218.74.156	A	pop.sbc.mail.vip.bf1.yahoo.com
66.218.74.175	PTR	unknown.yahoo.com
66.218.74.175	A	sg.f1117.mail.yahoo.com
66.218.74.175	A	mc1939.mail.yahoo.com
66.218.74.212	PTR	thumbp22.mail.vip.bf1.yahoo.com
66.218.74.212	A	incoming.yahoo.verizon.net
66.218.74.225	PTR	unknown-66-218-74-x.yahoo.com
66.218.74.235	A+PTR	mta-v1.grp.mail.vip.bf1.yahoo.com
66.218.74.235	A	fo-mx-groups.mail.am0.yahoodns.net
66.218.74.240	A+PTR	pop.rog.mail.vip.bf1.yahoo.com
66.218.74.240	A	pop.bloor.is.net.cable.rogers.com
66.218.74.240	A	pop.mail.rog.gm0.yahoodns.net
66.218.75.9	PTR	rpqname30101.mail.bf1.yahoo.com
66.218.75.11	PTR	rpqname30201.mail.bf1.yahoo.com
66.218.75.64	PTR	unknown-66-218-75-x.yahoo.com
66.218.75.65	A+PTR	ymas.oa.yahoo.com
66.218.75.67	A+PTR	ymas.oa.yahoo.com
66.218.75.95	PTR	mix141701.mail.bf1.yahoo.com
66.218.75.96	PTR	unknown-66-218-75-x.yahoo.com
66.218.75.96	A	htc.imap.mail.yahoo.com
66.218.75.96	A	imap.mail.am0.yahoodns.net
66.218.75.97	PTR	unknown-66-218-75-x.yahoo.com
66.218.75.97	A	imap.mail.am0.yahoodns.net
66.218.75.97	A	imap-ssl.mail.yahoo.com
66.218.75.98	PTR	unknown.yahoo.com
66.218.75.98	A	imap.mail.am0.yahoodns.net
66.218.75.98	A	imap-ssl.mail.yahoo.com
66.218.75.99	PTR	unknown-66-218-75-x.yahoo.com
66.218.75.99	A	htc.imap.mail.yahoo.com
66.218.75.99	A	imap.mail.am0.yahoodns.net
66.218.75.105	PTR	yas.oa.yahoo.com
66.218.75.206	PTR	web141415.mail.bf1.yahoo.com