dns13.fpt.vn has one IP number , but the reverse is dns1.hcm.fpt.vn. dns1.hcm.fpt.vn and isp-web.hcm.fpt.vn point to the same IP. adc.vn, lhc.vn, vcg.vn, lili.vn, sacc.vn and at least 100 other hosts use this as a nameserver. fpt.vn is delegated to two nameservers, however both delegated nameservers are missing in the zone and two other nameservers are listed instead. All nameservers are at fpt.vn themselves. Some of them are on the same IP network. Incoming mail for fpt.vn is handled by three mailservers also at fpt.vn. All of them are on the same IP network. dns13.fpt.vn is hosted on a server in Vietnam.