mx.itb.ac.id has one IP number , but the reverse is mx2.itb.ac.id. mx2.itb.ac.id point to the same IP. unikom.ac.id use this as a nameserver. tf.itb.ac.id, gd.itb.ac.id, ar.itb.ac.id, pl.itb.ac.id, pn.itb.ac.id and at least 100 other hosts use this as a mailserver. itb.ac.id is a domain controlled by six nameservers having a total of seven IP numbers. Some of them are on the same IP network. Incoming mail for itb.ac.id is handled by two mailservers having a total of three IP numbers. All of them are on the same IP network. itb.ac.id has one IP number. mx.itb.ac.id is hosted on a server in Indonesia.