Robtex

Up: 5.100.160.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 5.100.168.0/22
Down right: 5.100.172.0/22

IP	Type	Hostname
5.100.168.0	A+PTR	5-100-168-0.rdns.blackberry.net
5.100.168.96	A+PTR	5-100-168-96.rdns.blackberry.net
5.100.168.109	A	5-100-168-109.rdns.blackberry.net
5.100.168.114	A+PTR	5-100-168-114.rdns.blackberry.net
5.100.168.192	PTR	5-100-168-192.rdns.blackberry.net
5.100.169.0	A+PTR	5-100-169-0.rdns.blackberry.net
5.100.169.58	A+PTR	5-100-169-58.rdns.blackberry.net
5.100.169.117	A	5-100-169-117.rdns.blackberry.net
5.100.169.210	A+PTR	5-100-169-210.rdns.blackberry.net
5.100.169.241	A+PTR	5-100-169-241.rdns.blackberry.net
5.100.171.13	A	5-100-171-13.rdns.blackberry.net
5.100.171.22	A	5-100-171-22.rdns.blackberry.net
5.100.171.46	A	5-100-171-46.rdns.blackberry.net
5.100.171.55	A	5-100-171-55.rdns.blackberry.net
5.100.171.58	A+PTR	5-100-171-58.rdns.blackberry.net
5.100.171.81	A+PTR	5-100-171-81.rdns.blackberry.net
5.100.171.84	A	5-100-171-84.rdns.blackberry.net
5.100.171.91	A+PTR	5-100-171-91.rdns.blackberry.net
5.100.171.233	A+PTR	5-100-171-233.rdns.blackberry.net
5.100.172.0	A+PTR	5-100-172-0.rdns.blackberry.net
5.100.172.35	A+PTR	5-100-172-35.rdns.blackberry.net
5.100.172.54	A	5-100-172-54.rdns.blackberry.net
5.100.172.69	A	5-100-172-69.rdns.blackberry.net
5.100.172.86	A	5-100-172-86.rdns.blackberry.net
5.100.172.104	A+PTR	5-100-172-104.rdns.blackberry.net
5.100.172.109	A	5-100-172-109.rdns.blackberry.net
5.100.172.176	A+PTR	5-100-172-176.rdns.blackberry.net