Browse Prior Art Database

BGP Communities Attribute (RFC1997) Disclosure Number: IPCOM000004270D
Original Publication Date: 1996-Aug-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 4 page(s) / 8K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

R. Chandra: AUTHOR [+1]


Border Gateway Protocol [1] is an inter-autonomous system routing protocol designed for TCP/IP internets.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 36% of the total text.

Network Working Group R. Chandra

Request for Comments: 1997 P. Traina

Category: Standards Track cisco Systems

T. Li

August 1996

BGP Communities Attribute

Status of This Memo

This document specifies an Internet standards track protocol for the

Internet community, and requests discussion and suggestions for

improvements. Please refer to the current edition of the "Internet

Official Protocol Standards" (STD 1) for the standardization state

and status of this protocol. Distribution of this memo is unlimited.


Border Gateway Protocol [1] is an inter-autonomous system routing

protocol designed for TCP/IP internets.

This document describes an extension to BGP which may be used to pass

additional information to both neighboring and remote BGP peers.

The intention of the proposed technique is to aid in policy

administration and reduce the management complexity of maintaining

the Internet.


BGP supports transit policies via controlled distribution of routing

information. Mechanisms for this are described in [1] and have been

successfully used by transit service providers. However, control

over the distribution of routing information is presently based on

either IP address prefixes or on the value of the AS_PATH attribute

(or part of it).

To facilitate and simplify the control of routing information this

document suggests a grouping of destinations so that the routing

decision can also be based on the identity of a group. Such a scheme

is expected to significantly simplify a BGP speaker's configuration

that controls distribution of routing information.

Terms and Definitions


A community is a group of destinations which share some common


Each autonomous system administrator may define which communities

a destination belongs to. By default, all destinations belong to

the general Internet community.


A property such as "NSFNET sponsored/AUP" could be added to all AUP

compliant destinations advertised into the NSFNET. NSFNET operators

could define a policy that would advertise all routes, tagged or not,

to directly connected AUP compliant customers and only tagged routes

to commercial or external sites. This would insure that at least one

side of a given connection is AUP compliant as a way of enforcing NSF

transit policy ...