The Design And Implementation Of Virtual Router Redundancy System Based On Vrrpe

With the rapid development of Internet, the reliability and sustainability of network transmission are becoming more and more important. Today’s mainstream LAN networking technology is easy to form the situation of paralysis of the entire local area network due to a single router failure. This paper introduces the Virtual Router Redundancy system to solve this problem.Virtual Router Redundancy system is a fault-tolerant system of the routers. Through this technique, multiple routers are regarded as a single virtual router. Only one of the routers called master router is selected to transmit data, the others are backup routers. When the master router breaks down, the system ensures that one of the backup routers will be selected to be the master router and transmit data quickly. Thus, it ensures continuity and reliability of communications.One of the disclosure protocols supporting virtual routing redundancy system is VRRP (Virtual Router Redundancy Protocol), RFC3768. But there are certain shortcomings in VRRP. In simple networking, there is only one router in the set of routers make up the virtual router working. The others are just idle and wasting equipment and bandwidth.And also, the load balancing function of VRRP is not flexible enough. It is difficult to configure and not adaptive variable. In this context, a company presents the VRRPE (Extended Virtual Router Redundancy Protocol) based on the VRRP to solve the problems. By allocating different virtual MACs to the backup set routers and responding them to the LAN host’s ARP requests, the protocol implements the strategy of dynamic load sharing successfully. By VRRPE, the traffic of hosts in the LAN is distributed to the backup set of the routers averagely. When one of the routers fails, another one will replace it to transmit data. It truly implements the redundancy backup and load balancing, and no of the routers is wasting.This paper explains the basic principles of VRRPE in detail. Then it describs the devise and implementation of the system based on VRRPE and LINUX, including requirements analysis, one and two level module design, implementation of important modules, basic system testing. And finally it shows the summary and outlook of the advantages and disadvantages of the whole system.