A Heuristic Approach to Detect MPLS L3 VPN Misconfiguration in Multi-Homed Multi-VRF Site-Redundant CE Environments

Abstract

MPLS L3 VPNs are often configured manually and are prone to errors. Misconfigured VPNs violate customer’s privacy and security. With the advent of the Multi-VRF (VRF-Lite) feature on the CE, it is now possible to support two or more routing domains on a single CE. Customers can also add more CE devices in redundant configurations having multi-homed connections to service providers’ PE routers for enhanced reliability and high availability of MPLS L3 VPNs. This scenario adds more complexity increasing the reasonable probability of misconfiguration. MINA algorithm can detect errors in the MPLS infrastructure without the cooperation of the service providers. However, the MINA algorithm works for single-homed CE configured for a single VRF per CE. In this paper, we extend the MINA algorithm using a heuristic-based approach to detect misconfiguration in the MPLS infrastructure connected to Multi-VRF, Multi-homed, site-redundant CE environments. We effectively utilize both control-plane and data-plane information to demonstrate the detection of one-way and discovery of two-way RT (Route Targets) misconfiguration. The heuristic method can further detect the probable location/site and pinpoint the shared CE-customer affected by this misconfiguration.