Application Research On Cross Autonomous System VPN Based On MPLs And BGP

Built with Multi-Protocol Label Switching and Border Gateway Protocol, dynamic scalable Virtual Private Network is effective to solve address conflicts of different VPN users, mutual visits control, data isolation and other issues. It has been increasingly favored among all sorts of users.With the increasing size of the enterprise network it needs to be inter-autonomously linked, but the existing VPN and BGP built with MPLS don't support it. Therefore, the Internet working group is researching on inter-autonomous domains or interconnect problems between different VPN.The main contents of this dissertation are as follows:Firstly, the method of VPN is proposed by adopting BGP and MPLS in view of the defects in extensibility, manageability, address multiplexing and security among the virtual network by using the traditional VPN technology. The method forms a label forwarding path with dynamic properties through the MPLS label distribution, which a "bridge" is set up to create a channel for the private network data across the public network. Different VPN users employ the same private addresses resulting in addresses conflict. By using multiple processes, VRF(virtual routing technology), VPN instance, and BGP's attribute of RT, RD, LABLE, many questions have been solved, such as address multiplexing, data separation of different VPN users, VPN exchange control. The solutions of the questions proves the feasibility of the method.Secondly, the method of the back-to-back cross-domain network platform is put forward by analyzing some problems existing in the organizational construction of VPN network and the origins of these problems. Specific plans are made for device naming, IP address, routing protocols, BGP 's attribute of RT and RD to provide its guarantee for the smooth implementation of the program. Through the simulation experiments and the related experiment testing data, it shows that this method is better than the traditional VPN in terms of reliability, manageability, scalability and security.Finally, VPN network system based on MPLS and BGP has the problems that the labels path forward can't be formed in the cross-domain platform that autonomous system boundary equipments are overload. The causes are analyzed from the perspective of principle of MPLS label distribution and data forwarding platform. Two solutions have been put forward to eliminate the causes. The one is that many links and interface are not maintained to effectively reduce network management personnel's workload in the cross-domain platform construction. The other is that the public data and private network data of different VPN users are processed with different equipments to reduce the burden of autonomous system boundary equipment and to expand the application field of the VPN technology in the cross-domain platform of network system.