Study On Several Problems For Inter-domain MPLS VPN

A VPN is a network where customers have connectivity across a shared infrastructure using the same access and security policies as a.private network. In the course of research, we discovered several problems for inter-domain MPLS VPN.Aimed at the circumstance,Based on the NSF project Study on InterDomain Routing Stability and Managebility,in this dissertation, we put forward algorithms to automatically discover VPN topology,to detect MP-BGP misconfiguration on PE or ASBR,to manage the inter-domain routes and to effectively balance inter-domain traffic and to dynamically manage MPLS VPN path.Firstly, in order to grasp clearly the membership, we put forward to an algorithm to discover MPLS VPN topology. Algorithms aims at automating this VPN discovery procedure based on VRF and RT.Secondly, we put forward to the algorithm to detect MP-BGP misconfiguration on PE or ASBR in MPLS VPN. This algorithm can decrease the update load on routers, and avoid disrupting Internet connectivity. We mainly study the origin misconfiguration and export misconfiguration. In this method, the inbound routes and outbound routes are detected for origin errors according to the relationship between the prefixes and ASes which announce the prefixes. We use the commercial relationships between ASes to detect routes and further find routes violating export guidelines.Thirdly, in MPLS VPNs, traffic engineering achieved by using MPLS was predominantly limited to intra-domain and single administrative domain. However with the rapid expansion of enterprise scale, a VPN has spanned a large number of administrative domains. Thus effective management of inter-domain traffic is urgently demanded. We put forward to methodology to balance the inter-domain traffic in MPLS VPNs by BGP. Presented the simplest method is on the basis of various BGP attributes, BGP import or export routing policy and AS relationship constructed according to bilateral economical agreements. For this, they can rely on the LOCAL-PREF attribute to control the routes that will be chosen for the packets that leave each BGP router of the provider. In order to balancing incoming traffic, ASes are allowed announce their prefixes to a selected subset of providers instead of all providers.Finally, in MPLS VPN, the connectionless IP traffic of the VPN site transits MPLS backbone by connect-oriented LSP, in many cases, LSP was designed manually by network manager, we put forward to the algorithm to dynamically manage MPLS VPN path based on failure recover model. In this article, we present a methodology for MPLS VPN service management employing a resilience model. The methods can dynamically configure the service paths of MPLS VPN satisfying the TE resilience requirement from the customers. Specifically, we describe backup path design rules and derive the conditions for testing the availability of feasible backup paths satisfying the resilience constraints in a full mesh MPLS VPN. We present fast backup path construction algorithms which could make the MPLS VPN service to be available with minimal disruption, satisfying the resilience requirement from the customers.