hcm-server1.vnn.vn has one IP number , which also has a corresponding reverse pointer. 0.162.203.in-addr.arpa point to the same IP. abc.vn, hmc.vn, vnn.vn, vnsc.vn, s.vnn.vn and at least 100 other hosts use this as a nameserver. vnn.vn is a domain controlled by two nameservers at vnn.vn themselves. They are on different IP networks. Incoming mail for vnn.vn is handled by two mailservers having a total of 14 IP numbers. Some of them are on the same IP network. hcm-server1.vnn.vn is hosted on a server in Vietnam.