Robtex

Up: 5.42.80.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 5.42.80.0/22
Down right: 5.42.84.0/22

IP	Type	Hostname
5.42.80.3	PTR	5-42-80-3.colomna.net
5.42.80.146	PTR	5-42-80-146.colomna.net
5.42.81.59	PTR	5-42-81-59.colomna.net
5.42.81.153	PTR	5-42-81-153.colomna.net
5.42.83.137	PTR	5-42-83-137.colomna.net
5.42.83.145	PTR	5-42-83-145.colomna.net
5.42.83.152	PTR	5-42-83-152.colomna.net
5.42.83.153	PTR	5-42-83-153.colomna.net
5.42.83.185	PTR	5-42-83-185.colomna.net
5.42.83.216	PTR	5-42-83-216.colomna.net
5.42.83.217	PTR	5-42-83-217.colomna.net
5.42.84.74	PTR	5-42-84-74.colomna.net
5.42.86.209	PTR	5-42-86-209.colomna.net
5.42.87.1	PTR	5-42-87-1.colomna.net
5.42.87.153	PTR	5-42-87-153.colomna.net
5.42.87.210	PTR	5-42-87-210.colomna.net
5.42.87.217	PTR	5-42-87-217.colomna.net