Robtex

Up: 117.120.16.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 117.120.17.0/25
Down right: 117.120.17.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
117.120.17.20	PTR	unassigned.messagelabs.net
117.120.17.66	PTR	unassigned.messagelabs.net
117.120.17.68	PTR	proxy66.messagelabs.net
117.120.17.70	PTR	unassigned.messagelabs.net
117.120.17.74	PTR	unassigned.messagelabs.net
117.120.17.89	PTR	unassigned.messagelabs.net
117.120.17.94	PTR	unassigned.messagelabs.net
117.120.17.117	PTR	unassigned.messagelabs.net
117.120.17.158	PTR	unassigned.messagelabs.net
117.120.17.174	PTR	unassigned.messagelabs.net
117.120.17.175	PTR	unassigned.messagelabs.net
117.120.17.180	PTR	unassigned.messagelabs.net
117.120.17.212	PTR	unassigned.messagelabs.net
117.120.17.225	PTR	unassigned.messagelabs.net
117.120.17.227	PTR	unassigned.messagelabs.net
117.120.17.227	A	proxy69.messagelabs.net
117.120.17.254	PTR	proxy1.sg3.symsaas.net
117.120.17.254	A	proxy2.sg.webscanningservice.com
117.120.17.254	A	roaming1.sg.webscanningservice.com