Robtex

Up: 193.27.0.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 193.27.0.0/25
Down right: 193.27.0.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
193.27.0.3	A+PTR	mail1.quriusmail.com
193.27.0.4	A+PTR	mail2.quriusmail.com
193.27.0.19	A+PTR	ns1.quriuscloud.com
193.27.0.19	PTR	ns1.quriusmail.com
193.27.0.19	PTR	ns1.quriusmonitor.com
193.27.0.20	A+PTR	ns2.quriuscloud.com
193.27.0.20	PTR	ns2.quriusmail.com
193.27.0.20	PTR	ns2.quriusmonitor.com
193.27.0.187	A	medewerkers.savant-zorg.nl
193.27.0.221	A	arbizzcard.com
193.27.0.234	A	sps.oltmann.com
193.27.0.235	A	mx0.oltmann.org
193.27.0.235	A	exchange.oltmann.com
193.27.0.236	A+PTR	oltmann.quriuscloud.com
193.27.0.247	PTR	eml2010.quriusmail.com
193.27.0.247	A+PTR	hmc2010.quriusmail.com
193.27.0.247	PTR	testdomain.quriusmail.com
193.27.0.248	A+PTR	mgmt.quriuscloud.com
193.27.0.248	PTR	mgmtportal.quriuscloud.com
193.27.0.249	A+PTR	smtp1.quriuscloud.com
193.27.0.249	A+PTR	smtp1.quriusmail.com
193.27.0.249	A	mail.jade.nl
193.27.0.250	A+PTR	smtp2.quriuscloud.com
193.27.0.250	A+PTR	smtp2.quriusmail.com
193.27.0.250	A	pop.dekowood.nl