Traditional routers perform a series of complex operations when forwarding each packet, including route lookup, access control table matching, address resolution, priority management, and other additional operations. These operations greatly affect the performance and efficiency of the router, reduce the packet forwarding rate and forwarding throughput, and increase the burden on the CPU. The correlation between the packets before and after the router is very large, and the packets with the same destination address and source address often arrive continuously, which provides the possibility and basis for the fast forwarding of the packets. New-generation routers, such as IP Switch and Tag Switch, use this design idea to implement fast forwarding with hardware, thus greatly improving the performance and efficiency of the router.
Next-generation routers use forwarding caches to simplify forwarding of packets. In the fast forwarding process, it is only necessary to perform traditional routing and forwarding processing on the first few packets of a group of packets with the same destination address and source address, and the destination address, source address and next gateway address ( next router address) into the forwarding cache. When the subsequent packet is to be forwarded, the forwarding cache should be checked first. If the destination address and source address of the packet match those in the forwarding cache, it will be forwarded directly according to the next gateway address in the forwarding cache, without going through the traditional The complex operation of the router greatly reduces the burden of the router, thereby achieving the goal of improving the throughput of the router.
