Robtex

Up: 172.241.80.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 172.241.84.0/23
Down right: 172.241.86.0/23

IP	Type	Hostname
172.241.84.2	PTR	ns1.championarc.com
172.241.84.60	PTR	vpn0060.amazingugly.com
172.241.84.96	PTR	vpn0096.amazingugly.com
172.241.84.101	PTR	vpn00101.amazingugly.com
172.241.84.145	PTR	vpn00145.sitegrowl.com
172.241.86.2	PTR	ns1.wonderfulch.com
172.241.86.8	PTR	vpn008.powerfullgo.com
172.241.86.29	PTR	vpn0029.powerfullgo.com
172.241.86.106	PTR	vpn00106.enterprisesgluestick.com
172.241.86.130	PTR	vpn00130.enterprisesgluestick.com