Browse Prior Art Database

Capabilities Advertisement with BGP-4 (RFC2842)

IP.com Disclosure Number: IPCOM000003440D
Original Publication Date: 2000-May-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 [+2]

Abstract

Currently BGP-4 [BGP-4] requires that when a BGP speaker receives an OPEN message with one or more unrecognized Optional Parameters, the speaker must terminate BGP peering. This complicates introduction of new capabilities in BGP.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 39% of the total text.

Network Working Group R. Chandra

Request for Comments: 2842 Redback Networks Inc.

Category: Standards Track J. Scudder

cisco Systems

May 2000

Capabilities Advertisement with BGP-4

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.

Copyright Notice

Copyright (C) The Internet Society (2000). All Rights Reserved.

Abstract

Currently BGP-4 [BGP-4] requires that when a BGP speaker receives an

OPEN message with one or more unrecognized Optional Parameters, the

speaker must terminate BGP peering. This complicates introduction of

new capabilities in BGP.

This document defines new Optional Parameter, called Capabilities,

that is expected to facilitate introduction of new capabilities in

BGP by providing graceful capability advertisement without requiring

that BGP peering be terminated.

1. Overview of Operations

When a BGP speaker that supports capabilities advertisement sends an

OPEN message to its BGP peer, the message may include an Optional

Parameter, called Capabilities. The parameter lists the capabilities

supported by the speaker.

A BGP speaker determines the capabilities supported by its peer by

examining the list of capabilities present in the Capabilities

Optional Parameter carried by the OPEN message that the speaker

receives from the peer.

A BGP speaker that supports a particular capability may use this

capability with its peer after the speaker determines (as described

above) that the peer supports this capability.

A BGP speaker determines that its peer doesn't support capabilities

advertisement, if in response to an OPEN message that carries the

Capabilities Optional Parameter, the speaker receives a NOTIFICATION

message with the Error Subcode set to Unsupported Optional Parameter.

In this case the speaker should attempt to re-establish a BGP

connection with the peer without sending to the peer the Capabilities

Optional Parameter.

If a BGP speaker that supports a certain capability determines that

its peer doesn't support this capability, the speaker may send a

NOTIFICATION message to the peer, and terminate peering. The Error

Subcode in the message is set to Unsupported Capability. The message

should contain the capability (capabilities) that causes the speaker

to send the message. The decision to send the message and terminate

peering is local to the speaker. Such peering should not be re-

established automatically.

2. Capabilities Option...