Robtex

Up: 121.7.168.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 121.7.168.0/23
Down right: 121.7.170.0/23

IP	Type	Hostname
121.7.168.217	A+PTR	bb121-7-168-217.singnet.com.sg
121.7.169.47	A+PTR	bb121-7-169-47.singnet.com.sg
121.7.169.215	PTR	bb121-7-169-215.singnet.com.sg
121.7.170.137	PTR	bb121-7-170-137.singnet.com.sg
121.7.170.212	A+PTR	bb121-7-170-212.singnet.com.sg
121.7.170.229	A+PTR	bb121-7-170-229.singnet.com.sg
121.7.171.140	A+PTR	bb121-7-171-140.singnet.com.sg
121.7.171.230	PTR	bb121-7-171-230.singnet.com.sg