Robtex

Up: 222.255.0.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 222.255.0.0/25
Down right: 222.255.0.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
222.255.0.18	PTR	pgpextsrv.vks.gov.vn
222.255.0.21	PTR	ftp.vks.gov.vn
222.255.0.26	PTR	mail.vinalines.com.vn
222.255.0.27	A+PTR	mail.vinalines.com.vn
222.255.0.27	PTR	www.vinalines.com.vn
222.255.0.28	PTR	static.vnpt.vn
222.255.0.41	A+PTR	smtp.toaan.gov.vn
222.255.0.42	PTR	toaan.gov.vn
222.255.0.42	PTR	mailstore.toaan.gov.vn
222.255.0.42	A+PTR	pop3.toaan.gov.vn
222.255.0.43	A+PTR	mail.toaan.gov.vn
222.255.0.45	PTR	mail.toaan.gov.vn
222.255.0.46	PTR	static.vnpt.vn
222.255.0.46	A	namdinh.toaan.gov.vn
222.255.0.46	A	hatinh.toaan.gov.vn
222.255.0.70	PTR	static.vnpt.vn
222.255.0.100	PTR	mail.cavico.com.vn
222.255.0.100	PTR	mail.cavicovn.com.vn
222.255.0.114	PTR	mail.thanglongsc.com.vn
222.255.0.114	PTR	mail2.thanglongsc.com.vn
222.255.0.129	PTR	homer.abacuspos.com.vn
222.255.0.129	A	abacuspos.com.vn
222.255.0.172	PTR	static.vnpt.vn
222.255.0.187	PTR	vnab.abacuspos.com.vn
222.255.0.195	PTR	mx2.libertyinsurance.com.vn
222.255.0.234	PTR	static.vnpt.vn
222.255.0.250	PTR	mail.pvi.com.vn
222.255.0.251	PTR	smtp.pvi.com.vn