Robtex

Up: 111.221.64.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 111.221.64.0/23
Down right: 111.221.66.0/23

IP	Type	Hostname
111.221.64.67	PTR	po31-100.hkn-76gmr-mms-1b.ntwk.msn.net
111.221.66.19	PTR	hknprd0204.outlook.com
111.221.66.31	PTR	hknprd0302.outlook.com
111.221.66.47	PTR	xrop-hknprd0402.outlook.com
111.221.66.55	A+PTR	hknprd0502.outlook.com
111.221.66.55	A	hknprd0502m.outlook.com
111.221.67.13	A+PTR	hkn-40.spohealth.com
111.221.67.53	A+PTR	hkn-28.spohealth.com
111.221.67.81	A+PTR	hkn.mail.sharepointonline.com
111.221.67.83	A+PTR	hkn-35.spohealth.com