Research And Implementation Of Embedded Firewall

Along with the development of micro-electronic technology, the performance of embedded system has been greatly improved, the functions have been enhanced, and the application has been widely used.The traditional boundary firewall is the important means to grant the network security, but it can just provide protection against outside, not inside, and it is easily been cheated, and also there is network bottle neck. The embedded firewall is a new type of firewall based on the embedded system. It expanded the security strategy to the network end, and overcome the limit of the traditional boundary firewall, and provide to the enterprises with the perfect methods to settle the network security.EFW is to fix the firewall to the PCI network card, and all of the data packages in and out of the network card have to pass the security strategy of the firewall, and the make and delivery of the security strategy is accomplished by the strategy server. This kind of firewall is independent from host, isn't easy to be cheated and has flexible management. It is a more perfect security basic framework.This thesis introduces the design of software & hardware as well as the detailed implement of the EFW network card based on the ARM7TDMI processor, including choosing the style of micro-processor, the style of NIC chip, FLASH chip as well as SDRAM chip; the design of integer electro-circuit; the make of print board; the jointing of apparatus and component; and hardware debugging. EFW software design mainly includes programming of Bootloader, EFW card drive, and EFW package filtering; the transplant of uC/OS-II.The implement of EFW has been tested in LAN environment, and it is able to filter the data in and out of EFW network card according to the security strategy defined by the program.