Routing and connectivity in the Internet is largely governed by the
dynamics and configuration of the Border Gateway Protocol (BGP). A
configuration analysis toolkit enables network operators to discover,
analyze and diagnose their BGP configuration, policies and peering
relationships. Statistical variance analysis in such a toolkit exploits
the recurrence of policies in large networks for analysis. In a large
network, policies that have similar functions are examined, e.g. all
inbound route maps associated with customer autonomous systems. For n
occurrences of similar policy P, it is possible to flag k deviant
configurations, and evaluate the probability that the deviant
configurations are in error. Analysis and policy visualization of
implemented BGP configurations enable service providers to move from
checking of low-level configuration to extracting analyzable BGP level
policy information across a multitude of BGP routers in order to validate
consistency of policies and operator intent across distributed BGP
configurations using a flexible, customizable analysis engine