BGP communities

This document updates several BGP Extended Community registries in order to replace the "Experimental Use" registration procedure in some entries, since their use is clearly not experimental and is thus misleading.

This document updates RFCs 7153 and 8955.

Well-known BGP communities are manipulated differently across various current implementations, resulting in difficulties for operators. Network operators should deploy consistent community handling across their networks while taking the inconsistent behaviors from the various BGP implementations into consideration. This document recommends specific actions to limit future inconsistency: namely, BGP implementors must not create further inconsistencies from this point forward. These behavioral changes, though subtle, actually update RFC 1997.

By introducing new Information Elements (IEs), this document extends the existing BGP-related IEs to enable IP Flow Information Export (IPFIX) to export BGP community information, including the BGP Standard Communities defined in RFC 1997, BGP Extended Communities defined in RFC 4360, and BGP Large Communities defined in RFC 8092. According to the network operator's BGP community planning, network traffic information can then be accumulated and analyzed at the BGP community granularity, which represents the traffic of different kinds of customers, services, or geographical regions. Network traffic information at the BGP community granularity is useful for network traffic analysis and engineering.

This document presents examples and inspiration for operator application of BGP Large Communities. Based on operational experience with BGP Communities, this document suggests logical categories of BGP Large Communities and demonstrates an orderly manner of organizing community values within them to achieve typical goals in routing policy. Any operator can consider using the concepts presented as the basis for their own BGP Large Communities repertoire.

This document describes the BGP Large Communities attribute, an extension to BGP-4. This attribute provides a mechanism to signal opaque information within separate namespaces to aid in routing management. The attribute is suitable for use with all Autonomous System Numbers (ASNs) including four-octet ASNs.

This document reorganizes the IANA registries for the type values and sub-type values of the BGP Extended Communities attribute and the BGP IPv6-Address-Specific Extended Communities attribute. This is done in order to remove interdependencies among the registries, thus making it easier for IANA to determine which codepoints are available for assignment in which registries. This document also clarifies the information that must be provided to IANA when requesting an allocation from one or more of these registries. These changes are compatible with the existing allocations and thus do not affect protocol implementations. The changes will, however, impact the "IANA Considerations" sections of future protocol specifications. This document updates RFC 4360 and RFC 5701.

Current specifications of BGP Extended Communities (RFC 4360) support the IPv4 Address Specific Extended Community, but do not support an IPv6 Address Specific Extended Community. The lack of an IPv6 Address Specific Extended Community may be a problem when an application uses the IPv4 Address Specific Extended Community, and one wants to use this application in a pure IPv6 environment. This document defines a new BGP attribute, the IPv6 Address Specific Extended Community, that addresses this problem. The IPv6 Address Specific Extended Community is similar to the IPv4 Address Specific Extended Community, except that it carries an IPv6 address rather than an IPv4 address. [STANDARDS TRACK]

This document defines a new type of a BGP extended community, which carries a 4-octet Autonomous System (AS) number. [STANDARDS-TRACK]

This document describes the "extended community" BGP-4 attribute. This attribute provides a mechanism for labeling information carried in BGP-4. These labels can be used to control the distribution of this information, or for other applications. [STANDARDS-TRACK]

BGP communities (RFC 1997) are used by service providers for many purposes, including tagging of customer, peer, and geographically originated routes. Such tagging is typically used to control the scope of redistribution of routes within a provider's network and to its peers and customers. With the advent of large-scale BGP data collection (and associated research), it has become clear that the information carried in such communities is essential for a deeper understanding of the global routing system. This memo defines standard (outbound) communities and their encodings for export to BGP route collectors. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.

This document describes an extension to BGP which may be used to pass additional information to both neighboring and remote BGP peers. [STANDARDS-TRACK]

This document presents an application of the BGP community attribute [2] in simplifying the implementation and configuration of routing policies in the multi-provider Internet. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind.