Internet-Draft | BGP OPSEC | September 2024 |
Fiebig & Hilliard | Expires 3 April 2025 | [Page] |
The Border Gateway Protocol (BGP) is a critical component in the Internet to exchange routing information between network domains. Due to this central nature, it is important to understand the security and reliability requirements that can and should be ensured to prevent accidental or intentional routing disturbances.¶
Previously, security considerations for BGP have been described in RFC7454 / BCP194. Since the publications of RFC7454 / BCP194, several developments and changes in operational practice took place that warrant an update of these best current practices. This document replaces RFC7454 / BCP194, focusing on the overall goals, and providing a less implementation centric set of best practices.¶
To this end, the document describes the security requirements and goals when operating BGP for exchanging routing information with other networks. The document explicitly does not focus on specific technical implementations and requirements. Operators are advised to consult documentation and contemporary informational documents concerning methods to ensure that these properties are sufficiently ensured in their network.¶
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The Border Gateway Protocol (BGP), specified in [RFC4271], is the protocol used in the Internet to exchange routing information between network domains. BGP does not directly include mechanisms that control whether the routes exchanged conform to the various guidelines defined by the Internet community. Furthermore, the BGP protocol itself, by its design, does not have any direct way to protect itself against threats to confidentiality, integrity, and availability. This document summarizes security properties and requirements when operating BGP for securing the infrastructure as well as for security considerations regarding the exchanged routing information.¶
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.¶
The guidelines defined in this document are intended for BGP when used to exchange generic Internet routing information within the DFZ. It specifically does not cover other uses of BGP, e.g., when using BGP for NLRI exchange in a data-center context. This document does not specify how the outlined requirements and properties can be technically realized at a specific point in time. Instead, operators are advised to consult applicable documentation and contemporary informational documents describing implementation specifics.¶
The BGP speaker, i.e., the host running BGP to exchange routing information, needs to be protected from external attempts to taint integrity or availability of the BGP session and host alike.¶
To protect a BGP speaker on the network layer, an operator MUST ensure the following properties using technical or organizational measures:¶
In addition to the control plane / exchange of BGP protocol messages, the management plane of BGP speakers must be appropriately secured. Hence, operators MUST ensure that:¶
The purpose of BGP is exchanging routing information, i.e., NLRI. Importing or exporting incorrect or malicious NLRI is a security risk for networks themselves, but may also form a threat for connected and/or remote networks. As such, operators MUST ensure the following properties when importing or exporting routing information from their neighbors.¶
When importing NLRI from a neighbor, an operator MUST ensure that all imported NLRI conform to the following properties by implementing technical or organizational measures:¶
When originating NLRI or redistributing NLRI received from a neighbor, an operator MUST ensure that all NLRI they export conform to the following properties by implementing technical or organizational measures:¶
When processing NLRI, an operator MUST ensure that basic properties of these NLRI are not altered:¶
This document does not require any IANA actions.¶
This document is entirely about BGP operational security. It lists requirements and properties operators MUST ensure using technical or organizational measures when operating BGP routers in the DFZ.¶
However, it does not detail how the outlined properties and security requirements can be implemented and enforced in practice. This is a conscious choice given that available techniques and methods to ensure these properties will change over time, while the underlying principles remain the same.¶
Instead, readers MAY refer to the most recent non expired draft of [I-D.draft-fiebig-grow-routing-ops-sec-inform] for an updated list of currently available technology to ensure the above principles, and the most recent non expired draft of [I-D.draft-fiebig-grow-routing-ops-terms] for information on currently used terms and definitions in the context of global routing operations. Readers MUST NOT rely on expired versions of these I-Ds. If no most recent non-expired version of either I-D is available, the document MUST be considered to be non-existent.¶
This document has been originally based on [RFC7454] and we thank the original authors for their work.¶
We thank the following people for reviewing this draft and suggesting changes:¶