漫遊式通訊為電腦設備於移動至其它網段仍能維持網際網路服務所採行的一種通訊方式。漫遊機制中有兩個重要的議題:一、如何維持通訊連結不被中斷?二、如何進行身分認證?有關維持通訊連結不被中斷,在RFC3775中已有清楚的規範。在避免位址重覆使用的問題上面,於IPv6網路環境中有Duplicate Address Detection演算法可以避免網路位址重覆使用,然而此演算法尚無法延伸應用至漫遊環境之中。是以為了確保原網路位址只被合格的使用者使用,有必要建立身分認證的機制以識別使用者的身分及其合法使用的IP位址。 本文將根據Mobility IPv6及NEMO標準文件中所訂立的各項訊息封包格式及註冊處理流程,在遵循IPv6封包標頭格式的規定下,擴充標頭中相關的欄位置入身分認證訊息;並且在註冊處理流程之中,加入身分認證的處理程序,使漫遊機制得以更為完備。 Roaming communication is a way of communication for computer devices to maintain Internet services when they are moved to other networks. There are two critical issues in roaming communication: 1) How to maintain the communication while in roaming? And 2) How to authenticate the roaming node? To the first issue, RFC3775 has defined the solution clearly. In IPv6, there is an algorithm, Duplicate Address Detection (DAD), can be used to avoid an IP address being duplicate use, however, DAD cannot be extended to the roaming situation. Therefore, it is necessary to establish an authentication mechanism, in order to assure an IP address is legally used. This thesis defines the authentication message format in the IPv6 header according to Mobile IPv6 and NEMO standards. Meanwhile, an authentication procedure is then proposed in the registration process such that the roaming mechanism is more comprehensive.