The Amelioration On Transmit Performance Of A Multiple Export Gateway Based On Linux

Because the existence of different network lines belong to different network service providers,interconnection of different lines becomes the bottleneck of the rate of the users access the network.Therefore,many LANs begin to use multiple export gateway.The methods to solve the problem of multiple export in general:proxy server,routing plus NAT(Network Address Translation),policy routing,etc.Because the router with the function of policy routeing always so expensive,as a free Operating System,Linux provides strong functions of policy routing from kernel 2.1.Now,the Linux OS configured with policy routing begins to substitute router as the export gateway.Along with a deeper understanding of Linux,appear some gateway with flexble policy routing function realized through kernel programming.This thesis uses kernel programming implementing a multiple export gateway based on linux.It first researches the net framework of Linux kernel and considers shortening the journey of the packets travel in the kernel to promote the performance of the Linux gateway based on the research.Because the revision jumps over the Route System,the thesis constructs a new route system before transmitting the packet. The system reads these IP addresses that in common use to the route cache and constitutes the cache substitution arithmetic when constructing route cache.Aim at multiple export constructing special route table.Through optimizing route system to promote the performance of the gateway.It is hard that when the line in trouble choose another way in time for regular router.This thesis makes use of flexble programming realizing simple line redundancy.The system has passed the testing and reached the expected result.