Robtex

Up: 213.137.16.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 213.137.20.0/23
Down right: 213.137.22.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
213.137.20.11	PTR	host213.137.20.11.manx.net
213.137.20.11	A	mx1.geodrill-im.com
213.137.20.28	A+PTR	iom.circa.org.im
213.137.20.37	PTR	host213.137.20.37.manx.net
213.137.20.37	A	mail.bluesea.co.im
213.137.20.38	A	mail.cinemanx.com
213.137.20.53	A	mx1.kiartys.com
213.137.20.60	PTR	host213.137.20.60.manx.net
213.137.20.60	A	remote.ayrpower.com
213.137.20.60	A	totesamerica.com
213.137.20.77	PTR	host213.137.20.77.manx.net
213.137.20.77	A	mail.nasaleze.co.im
213.137.20.87	PTR	host213.137.20.87.manx.net
213.137.20.87	A	mail.goughco.com
213.137.20.95	PTR	host213.137.20.95.manx.net
213.137.20.95	A	mail.iomstorageandhandling.com
213.137.20.102	PTR	host213.137.20.102.manx.net
213.137.20.141	PTR	host213.137.20.141.manx.net
213.137.20.141	A	eipdata.com
213.137.20.211	PTR	host213.137.20.211.manx.net
213.137.20.211	A	exchange.pringle-law.com
213.137.20.222	PTR	host213.137.20.222.manx.net
213.137.20.222	A	mail.hpba.co.im
213.137.20.229	A+PTR	scms01.savagechadwick.com
213.137.20.238	PTR	host213.137.20.238.manx.net
213.137.20.238	A	mail.beckmanndirect.com
213.137.20.238	A	beckmanngroup.co.uk
213.137.20.253	PTR	host213.137.20.253.manx.net
213.137.20.253	A	mail.wdsltd.net
213.137.20.253	A	utm.wdsltd.net
213.137.21.58	A+PTR	mail.maximasystems.com
213.137.21.59	PTR	adsl213.137.21.59.manx.net
213.137.21.59	A	ns4.turf.org
213.137.21.59	A	ns2.turf.org
213.137.21.62	PTR	adsl213.137.21.62.manx.net
213.137.21.62	A	oxonsolutions.com
213.137.21.85	PTR	adsl213.137.21.85.manx.net
213.137.21.120	PTR	adsl213.137.21.120.manx.net
213.137.21.123	PTR	adsl213.137.21.123.manx.net
213.137.21.131	A	mail1.energyfm.net
213.137.21.133	PTR	irn.energyfm.net
213.137.21.133	PTR	adsl213.137.21.133.manx.net
213.137.21.217	PTR	remote.turnstone-europe.co.uk
213.137.21.217	A	mail.turnstone-europe.co.uk
213.137.21.217	A	w1.turnstone-europe.co.uk
213.137.21.251	PTR	adsl213.137.21.251.manx.net
213.137.21.251	A	mail.paradiseandgell.com
213.137.22.66	PTR	host213.137.22.66.manx.net
213.137.22.165	PTR	host213.137.22.165.manx.net
213.137.22.165	A	mail.sterling.im
213.137.22.199	PTR	host213.137.22.199.manx.net
213.137.22.199	A	mail.cjm.im
213.137.22.222	PTR	host213.137.22.222.manx.net
213.137.22.222	A	mail.castleiom.com
213.137.22.232	PTR	host213.137.22.232.manx.net
213.137.22.232	A	mail1.fiducs.com
213.137.23.14	PTR	host213.137.23.14.manx.net
213.137.23.20	PTR	host213.137.23.20.manx.net
213.137.23.23	PTR	webmail.seftonhotel.co.im
213.137.23.29	PTR	host213.137.23.29.manx.net
213.137.23.36	PTR	host213.137.23.36.manx.net
213.137.23.37	PTR	host213.137.23.37.manx.net
213.137.23.38	PTR	host213.137.23.38.manx.net
213.137.23.61	A+PTR	mail.freeportman.com
213.137.23.131	A+PTR	mail.blackgracecowley.com
213.137.23.218	A+PTR	mail.abacusiom.com
213.137.23.218	A	mail.abacus-asia.com
213.137.23.243	PTR	mail.cowley-groves.co.uk