Robtex

Up: 98.136.100.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 98.136.101.0/25
Down right: 98.136.101.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
98.136.101.0	PTR	unknown-98-136-101-x.yahoo.com
98.136.101.42	PTR	unknown-98-136-101-x.yahoo.com
98.136.101.88	PTR	unknown-98-136-101-x.yahoo.com
98.136.101.100	PTR	unknown-98-136-101-x.yahoo.com
98.136.101.112	A	sky300-aol-beta.mail.vip.gq1.yahoo.com
98.136.101.116	PTR	unknown.yahoo.com
98.136.101.116	A	mx-aol.mail.gm0.yahoodns.net
98.136.101.116	A	mta-v1.aol.mail.vip.gq1.yahoo.com
98.136.101.117	PTR	unknown.yahoo.com
98.136.101.117	A	mta-v43.mail.vip.gq1.yahoo.com
98.136.101.117	A	mta7.am0.yahoodns.net
98.136.101.121	PTR	unknown.yahoo.com
98.136.101.121	A	fo-fd-world-new.yax.gysm.yahoodns.net
98.136.101.122	PTR	jpop300-aol-sec.mail.vip.gq1.yahoo.com
98.136.101.122	A	global-jpop-aol.mail.gm0.yahoodns.net
98.136.101.138	PTR	unknown-98-136-101-x.yahoo.com
98.136.101.163	PTR	mtarelay.ops.vip.gq1.yahoo.net
98.136.101.163	A	mtarelay-new.am0.yahoodns.net
98.136.101.166	PTR	cads-int1-2035-002.raptor.adx.pool.ac4.yahoo.com
98.136.101.166	A	mrs1.mobile.a02.yahoodns.net
98.136.101.175	PTR	unknown.yahoo.com
98.136.101.175	A	yahoo.ac
98.136.101.175	A	yahoomalayalam.co.in
98.136.101.181	PTR	gdnp-ci-1002.raptor.adx.pool.ac4.yahoo.com
98.136.101.181	A	vzoprodextvip01.ygrid.vip.gq2.yahoo.com
98.136.101.182	A	help-contactus.a03.yahoodns.net
98.136.101.204	PTR	unknown-98-136-101-x.yahoo.com