Robtex

Up: 203.198.50.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 203.198.51.0/25
Down right: 203.198.51.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
203.198.51.1	A+PTR	001.51.198.203.static.netvigator.com
203.198.51.2	A+PTR	002.51.198.203.static.netvigator.com
203.198.51.3	A+PTR	003.51.198.203.static.netvigator.com
203.198.51.4	A+PTR	004.51.198.203.static.netvigator.com
203.198.51.5	A+PTR	005.51.198.203.static.netvigator.com
203.198.51.10	A+PTR	010.51.198.203.static.netvigator.com
203.198.51.11	A+PTR	011.51.198.203.static.netvigator.com
203.198.51.12	A+PTR	012.51.198.203.static.netvigator.com
203.198.51.13	A+PTR	013.51.198.203.static.netvigator.com
203.198.51.14	A+PTR	014.51.198.203.static.netvigator.com
203.198.51.17	PTR	017.51.198.203.static.netvigator.com
203.198.51.27	A	htcco.dyndns.org
203.198.51.50	PTR	050.51.198.203.static.netvigator.com
203.198.51.50	A	ns.mcafeedemo.com
203.198.51.50	A	www.mcafeedemo.com
203.198.51.52	A	mcafeedemo.com
203.198.51.56	A	ns.mcafeehk.com
203.198.51.77	PTR	077.51.198.203.static.netvigator.com
203.198.51.77	A	ipvpn009077.netvigator.com
203.198.51.82	A	ipvpn009082.netvigator.com
203.198.51.114	A	ipvpn009114.netvigator.com
203.198.51.115	PTR	smtp.chinaassets.com
203.198.51.115	PTR	smtp.mystockhk.com
203.198.51.115	A+PTR	smtp.firstshanghai.com.hk
203.198.51.116	A	wan1.wtcapital.com.hk
203.198.51.120	A+PTR	120.51.198.203.static.netvigator.com
203.198.51.121	A+PTR	mail.tsld.com
203.198.51.121	A	ipvpn009121.netvigator.com
203.198.51.121	A	mail1.taisangland.com.hk
203.198.51.172	A+PTR	172.51.198.203.static.netvigator.com
203.198.51.193	A+PTR	193.51.198.203.static.netvigator.com
203.198.51.203	A+PTR	203.51.198.203.static.netvigator.com
203.198.51.210	A	polyhkss.com