The Research And Realization Of Campus NAS Based On RADIUS Protocol

Campus network is an important indicator of basic construction and management of an institution of higher learning. But how to ensure working order of campus network from hackers has become an unavoidable pressing issue;on the other hand, while campus network facilitate the lives of students and teachers, it have also become an important media of harmful ideology. Network security and management increasingly worse, has become the tremendous obstacle of development and application of campus network.The RADIUS protocol is powerful in the authentication, authorization and accounting management, and has flexible and convenient expansion. And the Linux operating system with good openness and security nature, the Nerfilter firewall of above Core version 2.4, provides powerful packet filtering function.This dissertation had synthetically considered each kind of factor, applies RADIUS in the campus network, sets into the Network Access Server (NAS) used to authenticate, authorize and manage the internal user pass in and out the Internet from the campus network, and designs the NAS consistent with the security needs of the campus network security.The primary works of this dissertation includes as follows:1. The RADIUS technical characteristic and principle of operation are comprehensively introduced;on the basis of them, the data packet and system structure of RADIUS is analyzed. Then, the basic knowledge of core firewall based on the Netfilter is introduced, and framework structure, handling flow of data packet of Netfilter are analyzed.2. The design thought is proposed, and aims at the key question in the design thought, proposes the solution;finally the principle of operation of system is elaborated in detail, and put forward a comparative reasonable system model.3. On the base of system model, the campus NAS based on RADIUS protocol is realized, and the test work has been carried on the system. The test result indicates that, the system has basically achieved the anticipative purpose, has realized the authentication, authorization and management of campus network user.