Robtex

Up: 80.84.72.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 80.84.72.0/25
Down right: 80.84.72.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
80.84.72.1	PTR	gw-zetnet.mcr.uklinux.net
80.84.72.2	A+PTR	access1-router.mcr.uklinux.net
80.84.72.10	A+PTR	s11.uklinux.net
80.84.72.11	A+PTR	s1.uklinux.net
80.84.72.14	A	s4.uklinux.net
80.84.72.16	A	s6.uklinux.net
80.84.72.20	A+PTR	ns1.uklinux.net
80.84.72.21	A+PTR	mail.uklinux.net
80.84.72.21	A	mailv.uklinux.net
80.84.72.21	A	mail.definitesoftware.com
80.84.72.22	PTR	pop3.uklinux.net
80.84.72.23	PTR	news.uklinux.net
80.84.72.25	A+PTR	ns3.uklinux.net
80.84.72.30	A+PTR	nodial.uklinux.net
80.84.72.30	A	lfm.dialin.uklinux.net
80.84.72.30	A	*.dialin.uklinux.net
80.84.72.32	A	mail2.uklinux.net
80.84.72.33	A	mail3.uklinux.net
80.84.72.132	PTR	mail.businesshr.net