Robtex

Up: 117.20.16.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 117.20.20.0/23
Down right: 117.20.22.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
117.20.20.34	PTR	tw20-static34.tw1.com
117.20.20.36	PTR	tw20-static36.tw1.com
117.20.20.70	PTR	tw20-static70.tw1.com
117.20.20.70	A	tfntech.com
117.20.20.70	A	webmail.tfntech.com
117.20.20.157	PTR	tw20-static157.tw1.com
117.20.21.12	PTR	tw21-static12.tw1.com
117.20.21.21	PTR	tw21-static21.tw1.com
117.20.21.26	PTR	tw21-static26.tw1.com
117.20.21.71	PTR	tw21-static71.tw1.com
117.20.21.94	PTR	tw21-static94.tw1.com
117.20.21.98	PTR	tw21-static98.tw1.com
117.20.21.108	PTR	tw21-static108.tw1.com
117.20.21.108	A	portal.ucp.edu.pk
117.20.21.132	PTR	tw21-static132.tw1.com
117.20.21.176	PTR	tw21-static176.tw1.com
117.20.21.196	PTR	tw21-static196.tw1.com
117.20.21.232	PTR	tw21-static232.tw1.com
117.20.22.1	PTR	tw22-static1.tw1.com
117.20.22.13	PTR	tw22-static13.tw1.com
117.20.22.24	PTR	mail.iba.edu.pk
117.20.22.34	PTR	khimail.systemsltd.com
117.20.22.35	PTR	khimail.systemsltd.com
117.20.22.35	A	khi.systemsltd.com
117.20.22.36	PTR	khimail.systemsltd.com
117.20.22.37	PTR	khimail.systemsltd.com
117.20.22.38	PTR	khimail.systemsltd.com
117.20.22.39	PTR	khimail.systemsltd.com
117.20.22.40	PTR	khimail.systemsltd.com
117.20.22.41	PTR	khimail.systemsltd.com
117.20.22.42	PTR	khimail.systemsltd.com
117.20.22.43	PTR	khimail.systemsltd.com
117.20.22.44	PTR	khimail.systemsltd.com
117.20.22.45	PTR	khimail.systemsltd.com
117.20.22.46	PTR	khimail.systemsltd.com
117.20.22.47	PTR	khimail.systemsltd.com
117.20.22.57	PTR	rsh1.js.com
117.20.22.110	PTR	mail0.meezanbank.com
117.20.22.113	A+PTR	mx1.jubileelife.com
117.20.22.113	PTR	mx.njilife.com
117.20.22.113	A	mx1.jubileehealth.com
117.20.22.118	A+PTR	mx2.jubileelife.com
117.20.22.118	A+PTR	mx2.njilife.com
117.20.22.118	A	mx2.jubileehealth.com
117.20.22.122	PTR	tw22-static122.tw1.com
117.20.22.123	A	exchange.alfalahinsurance.com
117.20.22.124	A	mail.alfalahinsurance.com
117.20.22.125	PTR	tw22-static125.tw1.com
117.20.22.131	PTR	mail.bop.com.pk
117.20.22.132	PTR	mail.bop.com.pk
117.20.22.133	PTR	tw22-static133.tw1.com
117.20.22.136	PTR	mail.bop.com.pk
117.20.22.137	PTR	mail.bop.com.pk
117.20.22.138	PTR	tw22-static138.tw1.com
117.20.22.171	A	mail.atlashonda.com.pk
117.20.22.171	A	ahlkhi.atlashonda.com.pk
117.20.23.18	PTR	mail.tw1.com
117.20.23.34	A	smtp.tes.com.pk
117.20.23.35	PTR	tw23-static35.tw1.com
117.20.23.35	A	webmail.tw1.com
117.20.23.36	PTR	tw23-static36.tw1.com
117.20.23.36	A	p-exg-mhc01.tw1.com
117.20.23.37	PTR	tw1.com
117.20.23.91	PTR	tw23-static91.tw1.com
117.20.23.182	PTR	tw23-static182.tw1.com