Robtex

Up: 121.1.0.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 121.1.0.0/22
Down right: 121.1.4.0/22
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
121.1.0.19	PTR	fortunetobacco.com.ph
121.1.0.19	PTR	www.fortunetobacco.com.ph
121.1.0.41	PTR	mail.rusina.com.ph
121.1.0.42	PTR	mail.rusina.com.ph
121.1.0.49	PTR	mdf.letran.edu
121.1.1.0	A	otserver.net
121.1.1.1	A	*.adszui.com
121.1.1.1	A	yz121.com
121.1.1.130	A+PTR	server.mgeups.com.ph
121.1.3.3	PTR	webmail.ees.smartbroadband.net.ph
121.1.3.3	A	smartbroadband.net.ph
121.1.3.4	PTR	mail.smartwifi.com.ph
121.1.3.4	PTR	mail.ees.smartbroadband.net.ph
121.1.3.4	A	webmail.ees.smartbroadband.net.ph
121.1.3.9	A+PTR	mx2.smartbro.net
121.1.3.9	A+PTR	proxy.smartbro.net
121.1.3.9	A	smtp01.smartbroadband.net.ph
121.1.3.13	A	bro-portalgmm.smartbro.net
121.1.3.16	A+PTR	vip3.smartbro.net
121.1.3.20	A+PTR	vip4.smartbro.net
121.1.3.81	A+PTR	vip1.smartbro.net
121.1.3.82	A+PTR	vip2.smartbro.net
121.1.3.83	A+PTR	proxy.smartbro.net
121.1.3.83	A+PTR	smtp02.smartbroadband.net.ph
121.1.3.84	PTR	mx02.smartbroadband.net.ph
121.1.3.194	A+PTR	proxy-smtp2.smartbro.net
121.1.3.194	A+PTR	proxy.smartbro.net
121.1.3.194	A+PTR	proxy2.smartbro.net
121.1.3.197	PTR	ruf-gre.smartbro.net
121.1.3.198	PTR	mail.smartwifi.com.ph
121.1.3.199	PTR	ns2.smartbro.net
121.1.3.200	A+PTR	smtp.smartbroadband.net.ph
121.1.3.200	A	smtp2.smartbro.net
121.1.3.201	PTR	bro-portal.smartbro.net
121.1.3.202	PTR	channel-portal.smartbro.net
121.1.3.208	A+PTR	ns1.smartbro.net
121.1.3.214	PTR	airborne.gw.smartbro.net
121.1.3.214	A	acl1-137bts.gw.smartbro.net
121.1.3.214	A	www.smartbrowifi.com
121.1.3.216	PTR	smtp.smartbro.net
121.1.3.217	A+PTR	iwebmap.smartbro.net
121.1.3.225	PTR	mx2.ees-dev.smartbroadband.net.ph
121.1.3.238	A+PTR	pneaccess.smartbro.net
121.1.3.250	PTR	dns4.smartbro.net
121.1.3.250	A+PTR	ns4.smartbro.net
121.1.7.237	A	www.cignal.net
121.1.7.237	A	e0-mdmm-94-vi1-ige.cignal.net
121.1.7.237	A	e0-mdmm-90-vi1-ige.cignal.net