% APNIC found the following authoritative answer from: whois.apnic.net

% [whois.apnic.net]
% Whois data copyright terms    http://www.apnic.net/db/dbcopyright.html

% Information related to '2401:b800::/32'

% Abuse contact for '2401:b800::/32' is 'hm-changed@vnnic.vn'

inet6num:       2401:b800::/32
netname:        VTC-VN
descr:          VTC - Multimedia Corporation
descr:          23 Lac Trung, Vinh Tuy ward, Hai Ba Trung district, Ha Noi city
country:        VN
admin-c:        DHL7-AP
tech-c:         HNH10-AP
remarks:        For spamming matters, mail to tri.le@vtc.vn
mnt-by:         MAINT-VN-VNNIC
mnt-lower:      MAINT-VN-VTC
mnt-routes:     MAINT-VN-VTC
status:         ALLOCATED PORTABLE
mnt-irt:        IRT-VNNIC-AP
last-modified:  2019-07-30T01:52:13Z
source:         APNIC

irt:            IRT-VNNIC-AP
address:        Ha Noi, VietNam
phone:          +84-24-35564944
fax-no:         +84-24-37821462
e-mail:         hm-changed@vnnic.vn
abuse-mailbox:  hm-changed@vnnic.vn
admin-c:        NTTT1-AP
tech-c:         NTTT1-AP
auth:           # Filtered
mnt-by:         MAINT-VN-VNNIC
last-modified:  2026-04-21T02:07:47Z
source:         APNIC

person:         Dang Hoai Linh
address:        VTC-VN
country:        VN
phone:          +84-0912259269
e-mail:         tenmien.intecom@vtc.vn
nic-hdl:        DHL7-AP
mnt-by:         MAINT-VN-VNNIC
last-modified:  2019-07-31T01:04:49Z
source:         APNIC

person:         Hoang Ngoc Ha
address:        VTC-VN
country:        VN
phone:          +84-0974153567
e-mail:         hahn@vtc.vn
nic-hdl:        HNH10-AP
mnt-by:         MAINT-VN-VNNIC
last-modified:  2019-07-30T01:49:44Z
source:         APNIC

% Information related to '2401:b800::/32AS38248'

route6:         2401:b800::/32
descr:          VTC Multimedia Corporation
origin:         AS38248
mnt-by:         MAINT-VN-VTC
notify:         kien.hoang@vtc.vn
notify:         tri.le@vtc.vn
last-modified:  2016-07-19T04:59:34Z
source:         APNIC

% This query was served by the APNIC Whois Service version 1.88.48 (WHOIS-AU5)