Design And Implementation For EVRRP

With the development of the network applications, more and more users can access to the network. So the increasingly more network loads become a burden for the network routing machine. Traditionally, every host is configured a default gateway so that they can connect to the outside and maintain communication for each other. However, using a single point as the default gateway will bring risk. We can presume that if the default gateway fails to work for some reason, then all the hosts that have this single point configured as the default gateway will lose connectivity to the outside world. The network administrator can restore the network by changing the default gateway manually on every host. However, if the scales of the hosts are too large, the configuration will become more complex and become a burden for the network administrator. The Virtual Routing Redundancy Protocol (VRRP) proposed by IETF can resolve the problem, however, which has the defects.As the cooperation with H3C, aimed at optimizing and improving the VRRP protocol, this paper includes following parts based on the software engineering:First, give an introduction of the VRRP in detail, point out the advantages and defects respectively. Learn from the load balancing algorithms. Select the algorithm based on IP address, then proposed the extended VRRP protocol—EVRRP. Second, according to the software engineering, adopt the Waterfall Model strictly to guarantee the work in every stage. Third, Design and decompose the functions for EVRRP thoroughly. Keep the function of Finite State Machine (FSM). Propose the Virtual Forwarder (VF) to realize the load-balancing function. Extend the standard VRRP packet to four formats. Four, according to the feature of the development platform, divide the module, define and design the data structure, then complete the coding. Last, complete the software verification with three times system tests on time.