Robtex

Up: 203.81.40.0/22
Can't show all results, try to descend to a more specific CIDR
Down left: 203.81.40.0/24
Down right: 203.81.41.0/24
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
203.81.40.12	PTR	echo3.sembcorp.com.sg
203.81.40.14	PTR	echo4.sembcorp.com.sg
203.81.40.60	A	middleeastinsurancereview.com
203.81.40.77	PTR	mx01.rach.com.sg
203.81.40.103	PTR	mail.chc.org.sg
203.81.40.163	A	mail.sgssg.com
203.81.40.196	PTR	mail.itconnectsystems.com
203.81.40.196	A	mail2.bticonsultants.com
203.81.40.200	PTR	mail4.itconnectsystems.com
203.81.40.201	PTR	mail5.itconnectsystems.com
203.81.41.2	A+PTR	cat29-pas-a10.pacific.net.sg
203.81.41.76	PTR	server528.3inetwork.net
203.81.41.78	A	emamashop.com
203.81.41.79	PTR	email.3ii.com
203.81.41.79	A	mail.veeco.com.cn
203.81.41.142	A	ftp.justlogin.com
203.81.41.143	PTR	mars.justlogin.com
203.81.41.143	A	pop.scciob.edu.sg
203.81.41.143	A	pop3.sccci.org.sg
203.81.41.152	A+PTR	scipksci.pacific.net.sg
203.81.41.152	PTR	scipksci.idc.pacific.net.sg
203.81.41.153	PTR	cat29-pas-d4.pacific.net.sg
203.81.41.153	PTR	cat29-pas-d4.idc.pacific.net.sg
203.81.41.159	PTR	cat29-pas-d4-2.pacific.net.sg
203.81.41.159	PTR	cat29-pas-d4-2.idc.pacific.net.sg
203.81.41.167	A	dc-59361f36.gamekrowd.com
203.81.41.167	A	ns1.guatlo.com
203.81.41.167	A	ns1.sembuddy.com
203.81.41.169	PTR	wnvtoa.worldnetvisions.com
203.81.41.169	A	theoneacademy.edu.my
203.81.41.169	A	toa.my
203.81.41.177	A	ns1.ossteq.com
203.81.41.180	A	mail.acegroup.sg
203.81.41.181	PTR	wnv041pl.worldnetvisions.com
203.81.41.186	A	ns2.guatlo.com
203.81.41.186	A	ossteq005pl.ossteq.com
203.81.41.186	A	ns2.midnightsona.com
203.81.41.188	PTR	lsmail.litespeed.com.sg
203.81.41.188	A	ns2.ossteq.com
203.81.41.189	A	leewaytrans.com.sg
203.81.41.195	A	mail2.mohsengcranes.com
203.81.41.195	A	*.mohsengcranes.com
203.81.41.195	A	structuredcapital.sg
203.81.41.198	A	mail.goggle.biz
203.81.41.198	A	pop.brain-dancing.com
203.81.41.198	A	pop.rajeshhardwani.com
203.81.41.199	A	mail.vconet.com
203.81.41.201	A	mail.thepublicrelationscompany.com.sg
203.81.41.201	A	mail.prestigesmartchef.com
203.81.41.201	A	mail.schick.com.sg
203.81.41.242	PTR	vinylmedia.com