By default reject propagation when no policy is associated with a BGP peering session.

BGP speakers have many default settings which need to be revisited as part of improving the routing ecosystem. There is a need to provide guidance to BGP implementors for the default behaviors of a well functioning internet ecosystem. Routing leaks are part of the problem, but software defects and operator misconfigurations are just a few of the attacks on internet stability we aim to address. Usually BGP speakers accept all routes from a configured peer or neighbor. This practice dates back to the early days of internet protocols in being very permissive in offering routing information to allow all networks to reach each other. With the core of the internet becoming more densely interconnected the risk of a misbehaving edge device or BGP speaking customer poses signficiant risks to the reachability of critical services. This proposal intends to solve this situation by requiring the explicit configuration of BGP policy for any non-iBGP speaking session such as customers, peers or confederation boundaries. When this solution is implemented, devices will no longer pass routes without explicit policy.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.

The following requirements apply to the solution described in this document: Software MUST mark any routes from an eBGP peer as 'invalid' in the Adj-RIB-In, if no explicit policy was configured. Software MUST NOT advertise any routes to an eBGP peer without an operator configuring a policy. Software MUST NOT require a configuration directive to operate in this mode. Software MUST provide protection from internal failures preventing the advertisement and acceptance of routes. Software MAY provide a configuration option to disable this security capability.

The authors would like to thank the following people for their comments and support: Shane Amante, Christopher Morrow, Robert Raszuk, Greg Skinner.

This document addresses the basic security posture of a BGP speaking device within a network. Operators have a need for implementors to address the problem through a behavior change to mitigate against possible attacks from a permissive security posture. Attacks and inadvertent advertisements cause business impact necessitating this default behavior.

This document has no actions for IANA.