Robtex

Up: 115.79.80.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 115.79.80.0/23
Down right: 115.79.82.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
115.79.80.19	PTR	adsl.viettel.vn
115.79.80.19	A	ns1.tenten.vn.sucohuephuong.com
115.79.80.19	A	mail.sucohuephuong.com
115.79.80.208	PTR	adsl.viettel.vn
115.79.81.40	PTR	adsl.viettel.vn
115.79.81.237	PTR	adsl.viettel.vn
115.79.82.138	PTR	adsl.viettel.vn
115.79.82.140	PTR	adsl.viettel.vn
115.79.82.148	PTR	adsl.viettel.vn
115.79.82.166	PTR	adsl.viettel.vn
115.79.82.171	PTR	adsl.viettel.vn
115.79.82.174	PTR	adsl.viettel.vn
115.79.82.252	PTR	adsl.viettel.vn