Robtex

Up: 212.21.0.0/18
Can't show all results, try to descend to a more specific CIDR
Down left: 212.21.32.0/20
Down right: 212.21.48.0/20
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
212.21.32.0	PTR	static-0.32.21.212.in-addr.arpa
212.21.32.97	PTR	static-97.32.21.212.in-addr.arpa
212.21.32.128	PTR	static-128.32.21.212.in-addr.arpa
212.21.32.226	PTR	static-226.32.21.212.in-addr.arpa
212.21.33.0	PTR	static-0.33.21.212.in-addr.arpa
212.21.34.12	A	www.bcc.cd
212.21.34.13	A	mail03.bcc.cd
212.21.34.14	A	mail.bcc.cd
212.21.34.16	A	mail02.bcc.cd
212.21.34.99	PTR	static-99.34.21.212.in-addr.arpa
212.21.34.160	PTR	static-160.34.21.212.in-addr.arpa
212.21.35.66	PTR	static-66.35.21.212.in-addr.arpa
212.21.36.123	A	mail.agentur-beham.de
212.21.40.35	PTR	static-35.40.21.212.in-addr.arpa
212.21.40.54	A	mail.togosh.com
212.21.40.66	PTR	static-66.40.21.212.in-addr.arpa
212.21.40.96	PTR	static-96.40.21.212.in-addr.arpa
212.21.40.220	A	newforum.chickenkiller.com
212.21.40.220	A	auberdine.etowns.net
212.21.40.220	A	sendmessage.mooo.com
212.21.41.0	PTR	static-0.41.21.212.in-addr.arpa
212.21.44.2	PTR	static-2.44.21.212.in-addr.arpa
212.21.44.2	A	mail.unfpa.or.ug
212.21.44.3	A+PTR	mail2.unfpa.or.ug
212.21.46.0	PTR	static-0.46.21.212.in-addr.arpa
212.21.46.98	PTR	static-98.46.21.212.in-addr.arpa
212.21.46.98	A	mx3.procreditbank-sl.com
212.21.46.98	A	mail.procreditbank-sl.com
212.21.46.99	PTR	static-99.46.21.212.in-addr.arpa
212.21.46.99	A	mx4.procreditbank-sl.com
212.21.48.34	PTR	static-34.48.21.212.in-addr.arpa
212.21.48.117	A	mx1.eupol-afg.eu
212.21.48.118	A	mx2.eupol-afg.eu
212.21.52.110	A	scrabble.ikwb.com
212.21.52.110	A	ceremon.2waky.com
212.21.52.110	A	nexus.x24hr.com
212.21.52.234	A	justice4all.twilightparadox.com
212.21.52.239	A	newgame.2waky.com
212.21.52.239	A	webonline.mefound.com
212.21.52.239	A	locker.strangled.net
212.21.53.234	A	speednet-emc.com
212.21.53.234	A	speednet-emc.org
212.21.53.234	A	speednet-emc.net
212.21.55.140	A	ns0.emc-corp.net
212.21.55.141	A	ns1.emc-corp.net
212.21.57.35	PTR	webmail.cub.paho.org
212.21.57.35	A	opscub1.ops-oms.org
212.21.57.46	A	emcglobalcell.com
212.21.57.117	A	myemclink.com
212.21.57.117	A	intranet.emc-corp.net
212.21.59.4	A	unama-mail.org
212.21.59.225	PTR	static-225.59.21.212.in-addr.arpa
212.21.60.224	PTR	static-224.60.21.212.in-addr.arpa
212.21.63.128	PTR	static-128.63.21.212.in-addr.arpa