Robtex

Up: 203.98.138.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 203.98.138.0/25
Down right: 203.98.138.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
203.98.138.26	A+PTR	rhv.nwtbb.com
203.98.138.115	PTR	mail.rainbowmaritimeltd.com
203.98.138.115	PTR	mail3.thisisrainbow.com
203.98.138.115	A	mail.rainbowlandasia.com
203.98.138.131	A+PTR	mail01.hkcec.com
203.98.138.131	A	mail01.shenyangnwexpo.com
203.98.138.131	A	mail01.nwsvml.com
203.98.138.132	A+PTR	mr01.hkcec.com
203.98.138.132	A	mr01.nwsvml.com
203.98.138.132	A	mr01.hkticketing.com
203.98.138.135	PTR	mail02.hkcec.com
203.98.138.136	PTR	mr01.hkticketing.com
203.98.138.137	A+PTR	mail05.hkcec.com
203.98.138.137	A	mail05.hkticketing.com