CISCO Systems NIL SpaceNet BGP (Border Gateway Protocol) is the protocol almost exclusively used in the Internet to exchange routing information between network domains. Due to this central nature, it's important to understand the security measures that can and should be deployed to prevent accidental or intentional routing disturbances. This document describes measures to protect the BGP sessions itself (like TTL, MD5, control plane filtering) and to better control the flow of routing information, using prefix filtering and automatization of prefix filters, max-prefix filtering, AS path filtering, route flap dampening and BGP community scrubbing.