Robtex

Up: 210.4.0.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 210.4.0.0/23
Down right: 210.4.2.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
210.4.2.4	PTR	ns01.bti.net.ph
210.4.2.6	PTR	smtp3.bti.net.ph
210.4.2.7	PTR	aaa1-dil.bti.net.ph
210.4.2.8	PTR	ns2.dil.bti.net.ph
210.4.2.9	PTR	ns3.dil.bti.net.ph
210.4.2.14	A+PTR	aaa2-dil.bti.net.ph
210.4.2.15	A	aaa2b.dil.bti.net.ph
210.4.2.49	PTR	smtp2-dil.bti.net.ph
210.4.2.50	A+PTR	vsf-mx1.bti.net.ph
210.4.2.61	PTR	nsvip-dil.bti.net.ph
210.4.3.2	A	mx3.emc.com.ph
210.4.3.2	A	mxbt.dot.ph
210.4.3.2	A	avmx1.domains.ph
210.4.3.52	PTR	pop.skybroadband.com.ph
210.4.3.52	A	dev-server.bti.net.ph
210.4.3.54	PTR	smtp.skybroadband.com.ph
210.4.3.56	PTR	dev-server.bti.net.ph
210.4.3.233	PTR	ns.mahjong88.com