The invention provides a method for Diameter prefix authorization. The method includes sending a request for a prefix by a Prefix Authorization (PA) client or Diameter client to a Prefix Authorization (PA) server or Diameter server. The method also includes replying with an answer message by the PA server to the PA client to provide a first prefix with a first lifetime. The invention further includes a method for initiating IPv6 address renumbering by sending a message for renumbering from the PA server. The method also includes receiving the message by the PA client and sending a message to the PA server to acquire a second prefix. The method further includes receiving the second prefix from the PA server with an answer message with a second lifetime, where the second prefix is different from the first prefix.