Definitions of Managed Objects

for the Border Gateway Protocol (Version 3)

Status of this Memo

This memo is an extension to the SNMP MIB. This RFC specifies an IAB standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "IAB Official Protocol Standards" for the standardization state and status of this protocol. Distribution of this memo is unlimited.

1. Abstract

This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in TCP/IP-based internets. In particular, it defines objects for managing the Border Gateway Protocol [11,12].

2. The Network Management Framework

The Internet-standard Network Management Framework consists of three components. They are:

RFC 1155 which defines the SMI, the mechanisms used for describing and naming objects for the purpose of management. RFC 1212 defines a more concise description mechanism, which is wholly consistent with the SMI.

RFC 1156 which defines MIB-I, the core set of managed objects for the Internet suite of protocols. RFC 1213, defines MIB-II, an evolution of MIB-I based on implementation experience and new operational requirements.

RFC 1157 which defines the SNMP, the protocol used for network access to managed objects.

The Framework permits new objects to be defined for the purpose of experimentation and evaluation.

3. Objects

Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. Objects in the MIB are defined using the subset of Abstract Syntax Notation One (ASN.1) [7] defined in the SMI. In particular, each object has a name, a syntax, and an encoding. The name is an object identifier, an administratively assigned name, which specifies an object type. The object type together with an object instance serves to uniquely identify a specific instantiation of the object. For human convenience, we often use a textual string, termed the OBJECT DESCRIPTOR, to also refer to the object type.

The syntax of an object type defines the abstract data structure corresponding to that object type. The ASN.1 language is used for this purpose. However, the SMI [3] purposely restricts the ASN.1 constructs which may be used. These restrictions are explicitly made for simplicity.

The encoding of an object type is simply how that object type is represented using the object type's syntax. Implicitly tied to the notion of an object type's syntax and encoding is how the object type is represented when being transmitted on the network.

The SMI specifies the use of the basic encoding rules of ASN.1 [8], subject to the additional requirements imposed by the SNMP.

3.1. Format of Definitions

Section 5 contains contains the specification of all object types contained in this MIB module. The object types are defined using the conventions defined in the SMI, as amended by the extensions specified in [9,10].

4. Overview

These objects are used to control and manage a BGP [11,12] implementation.

The Border Gateway Protocol (BGP) is an inter-Autonomous System routing protocol. The primary function of a BGP speaking system is to exchange network reachability information with other BGP systems. This network reachability information includes information on the full path of Autonomous Systems that traffic must transit to reach these networks.

BGP runs over a reliable transport protocol. This eliminates the need to implement explicit update fragmentation, retransmission, acknowledgement, and sequencing. Any authentication scheme used by the transport protocol may be used in addition to BGP's own authentication mechanisms.

The planned use of BGP in the Internet environment, including such issues as topology, the interaction between BGP and IGPs, and the enforcement of routing policy rules is presented in a companion document [12].

Apart from a few system variables, this MIB is broken into two tables: the BGP Peer Table and the BGP Received Path Attribute Table. The Peer Table reflects information about BGP peer connections, such as their state and current activity. The Received Path Attribute Table contains all attributes received from all peers before local routing policy has been applied. The actual attributes used in determining a route are a subset of the received attribute table.

5. Definitions

RFC1269-MIB DEFINITIONS ::= BEGIN

IMPORTS

                    NetworkAddress, IpAddress, Counter
                         FROM RFC1155-SMI
                    mib-2
                         FROM RFC1213-MIB
                  OBJECT-TYPE
                         FROM RFC-1212
                    TRAP-TYPE
                         FROM RFC-1215;
               
               -- This MIB module uses the extended OBJECT-TYPE macro as
               -- defined in [9], and the TRAP-TYPE macro as defined
               -- in [10].

bgp OBJECT IDENTIFIER ::= { mib-2 15 }

bgpVersion OBJECT-TYPE

SYNTAX OCTET STRING
ACCESS read-only
STATUS mandatory
DESCRIPTION

"Vector of supported BGP protocol version numbers. Each peer negotiates the version from this vector. Versions are identified via the string of bits contained within this object. The first octet contains bits 0 to 7, the second octet contains bits 8 to 15, and so on,

                         with the most significant bit referring to the
                         lowest bit number in the octet (e.g., the MSB
                         of the first octet refers to bit 0).  If a bit,
                         i, is present and set, then the version (i+1)
                         of the BGP is supported."
                    ::= { bgp 1 }

bgpLocalAs OBJECT-TYPE

                    SYNTAX INTEGER (0..65535)
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The local autonomous system number."
                    ::= { bgp 2 }

bgpPeerTable OBJECT-TYPE

                    SYNTAX SEQUENCE OF BgpPeerEntry
                    ACCESS not-accessible
                    STATUS mandatory
                    DESCRIPTION
                         "The bgp peer table."
                    ::= { bgp 3 }

bgpIdentifier OBJECT-TYPE

                    SYNTAX IpAddress
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The BGP Identifier of local system."
                    ::= { bgp 4 }

bgpPeerEntry OBJECT-TYPE

                    SYNTAX BgpPeerEntry
                    ACCESS not-accessible
                    STATUS mandatory
                    DESCRIPTION
                         "Information about a BGP peer connection."
                    INDEX
                         { bgpPeerRemoteAddr }
                        ::= { bgpPeerTable 1 }

BgpPeerEntry ::= SEQUENCE {

                    bgpPeerIdentifier
                         IpAddress,
                    bgpPeerState
                         INTEGER,
                    bgpPeerAdminStatus
                         INTEGER,
                    bgpPeerNegotiatedVersion
                         INTEGER,
                    bgpPeerLocalAddr
                         IpAddress,
                    bgpPeerLocalPort
                         INTEGER,
                    bgpPeerRemoteAddr
                         IpAddress,
                    bgpPeerRemotePort
                         INTEGER,
                    bgpPeerRemoteAs
                         INTEGER,
                    bgpPeerInUpdates
                         Counter,
                    bgpPeerOutUpdates
                         Counter,
                    bgpPeerInTotalMessages
                         Counter,
                    bgpPeerOutTotalMessages
                         Counter,
                    bgpPeerLastError
                         OCTET STRING
                    }

bgpPeerIdentifier OBJECT-TYPE

                    SYNTAX IpAddress
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The BGP Identifier of this entry's BGP peer."
                    ::= { bgpPeerEntry 1 }

bgpPeerState OBJECT-TYPE

                    SYNTAX INTEGER {
                         idle(1),
                         connect(2),
                         active(3),
                         opensent(4),
                         openconfirm(5),
                         established(6)
                    }
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The bgp peer connection state. "
                    ::= { bgpPeerEntry 2 }

bgpPeerAdminStatus OBJECT-TYPE

                    SYNTAX INTEGER
                    ACCESS read-write
                    STATUS mandatory
                    DESCRIPTION
                         "The desired state of the BGP connection. A
                         transition from 'stop' to 'start' will cause
                         the BGP Start Event to be generated. A
                         transition from 'start' to 'stop' will cause
                         the BGP Stop Event to be generated. This
                         parameter can be used to restart BGP peer
                         connections.  Care should be used in providing
                         write access to this object without adequate
                         authentication."
                    ::= { bgpPeerEntry 3 }

bgpPeerNegotiatedVersion OBJECT-TYPE

                    SYNTAX INTEGER
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The negotiated version of BGP running between
                         the two peers. "
                    ::= { bgpPeerEntry 4 }

bgpPeerLocalAddr OBJECT-TYPE

                    SYNTAX IpAddress
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The local IP address of this entry's BGP
                         connection."
                    ::= { bgpPeerEntry 5 }

bgpPeerLocalPort OBJECT-TYPE

                    SYNTAX INTEGER (0..65535)
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The local port for the TCP connection between
                         the BGP peers."
                    ::= { bgpPeerEntry 6 }

bgpPeerRemoteAddr OBJECT-TYPE

SYNTAX IpAddress
ACCESS read-only
STATUS mandatory
DESCRIPTION

                         "The remote IP address of this entry's BGP
                         peer."
                    ::= { bgpPeerEntry 7 }

bgpPeerRemotePort OBJECT-TYPE

                    SYNTAX INTEGER (0..65535)
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The remote port for the TCP connection between
                         the BGP peers.  Note that the objects
                         bgpLocalAddr, bgpLocalPort, bgpRemoteAddr and
                         bgpRemotePort provide the appropriate reference
                         to the standard MIB TCP connection table."
                    ::= { bgpPeerEntry 8 }

bgpPeerRemoteAs OBJECT-TYPE

                    SYNTAX INTEGER (0..65535)
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The remote autonomous system number."
                    ::= { bgpPeerEntry 9 }

bgpPeerInUpdates OBJECT-TYPE

                    SYNTAX Counter
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The number of BGP UPDATE messages received on
                         this connection. This object should be
                         initialized to zero when the connection is
                         established."
                    ::= { bgpPeerEntry 10 }

bgpPeerOutUpdates OBJECT-TYPE

                    SYNTAX Counter
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The number of BGP UPDATE messages received on
                         this connection. This object should be
                         initialized to zero when the connection is
                         established."
                    ::= { bgpPeerEntry 11}

bgpPeerInTotalMessages OBJECT-TYPE

                    SYNTAX Counter
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The total number of messages received from the
                         remote peer on this connection. This object
                         should be initialized to zero when the
                         connection is established."
                    ::= { bgpPeerEntry 12 }

bgpPeerOutTotalMessages OBJECT-TYPE

                    SYNTAX Counter
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The total number of messages transmitted to
                         the remote peer on this connection. This object
                         should be initialized to zero when the
                         connection is established."
                    ::= { bgpPeerEntry 13 }

bgpPeerLastError OBJECT-TYPE

                    SYNTAX OCTET STRING (SIZE (2))
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The last error code and subcode seen by this
                         peer on this connection. If no error has
                         occurred, this field is zero. Otherwise, the
                         first byte of this two byte OCTET STRING
                         contains the error code; the second contains
                         the subcode."
                    ::= { bgpPeerEntry 14 }

bgpRcvdPathAttrTable OBJECT-TYPE

                    SYNTAX SEQUENCE OF BgpPathAttrEntry
                    ACCESS not-accessible
                    STATUS mandatory
                    DESCRIPTION
                         "The BGP Received Path Attribute Table contains
                         information about paths to destination networks
                         received by all peers."
                    ::= { bgp 5 }

bgpPathAttrEntry OBJECT-TYPE

SYNTAX BgpPathAttrEntry
ACCESS not-accessible
STATUS mandatory
DESCRIPTION

                         "Information about a path to a network."
                    INDEX
                         { bgpPathAttrDestNetwork,
                           bgpPathAttrPeer }
                    ::= { bgpRcvdPathAttrTable 1 }

BgpPathAttrEntry ::= SEQUENCE {

                    bgpPathAttrPeer
                         IpAddress,
                    bgpPathAttrDestNetwork
                         IpAddress,
                    bgpPathAttrOrigin
                         INTEGER,
                    bgpPathAttrASPath
                         OCTET STRING,
                    bgpPathAttrNextHop
                         IpAddress,
                    bgpPathAttrInterASMetric
                         INTEGER
                    }

bgpPathAttrPeer OBJECT-TYPE

                    SYNTAX IpAddress
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The IP address of the peer where the path
                         information
                          was learned."
                    ::= { bgpPathAttrEntry 1 }

bgpPathAttrDestNetwork OBJECT-TYPE

                    SYNTAX IpAddress
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The address of the destination network."
                    ::= { bgpPathAttrEntry 2 }

bgpPathAttrOrigin OBJECT-TYPE

                    SYNTAX INTEGER {
                         igp(1),-- networks are interior
                         egp(2),-- networks learned via EGP
                         incomplete(3) -- undetermined
                    }
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The ultimate origin of the path information."
                    ::= { bgpPathAttrEntry 3 }

bgpPathAttrASPath OBJECT-TYPE

SYNTAX OCTET STRING
ACCESS read-only
STATUS mandatory
DESCRIPTION

"The set of ASs that must be traversed to reach the network. ( This object is probably best represented as SEQUENCE OF INTEGER. For SMI compatibility, though, it is represented as OCTET STRING. Each AS is represented as a pair of octets according to the following algorithm:

                              first-byte-of-pair = ASNumber / 256;
                              second-byte-of-pair = ASNumber & 255;"
                    ::= { bgpPathAttrEntry 4 }

bgpPathAttrNextHop OBJECT-TYPE

                    SYNTAX IpAddress
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The address of the border router that should
                         be used for the destination network."
                    ::= { bgpPathAttrEntry 5 }

bgpPathAttrInterASMetric OBJECT-TYPE

                    SYNTAX IpAddress
                    ACCESS read-only
                    STATUS mandatory
                    DESCRIPTION
                         "The optional inter-AS metric. If this
                         attribute has not been provided for this route,
                         the value for this object is 0."
                    ::= { bgpPathAttrEntry 6 }

bgpEstablished TRAP-TYPE

                    ENTERPRISE { bgp }
                    VARIABLES  { bgpPeerRemoteAddr,
                              bgpPeerLastError,
                              bgpPeerState }
                    DESCRIPTION
                         "The BGP Established event is generated when
                         the BGP FSM enters the ESTABLISHED state. "
                    ::= 1
               
               bgpBackwardTransition TRAP-TYPE
                    ENTERPRISE { bgp }
                    VARIABLES  { bgpPeerRemoteAddr,
                              bgpPeerLastError,
                              bgpPeerState }
                    DESCRIPTION
                         "The BGPBackwardTransition Event is generated
                         when the BGP FSM moves from a higher numbered
                         state to a lower numbered state."
                    ::= 2
               END

6. Acknowledgements

We would like to acknowledge the assistance of all the members of the Interconnectivity Working Group, and particularly the following individuals:

Yakov Rekhter, IBM
Rob Coltun, University of Maryland
Guy Almes, Rice University
Jeff Honig, Cornell Theory Center
Marshall T. Rose, PSI, Inc.
Dennis Ferguson, University of Toronto
Mike Mathis, PSC

7. References

   [1] Cerf, V., "IAB Recommendations for the Development of Internet
   
       Network Management Standards", RFC 1052, NRI, April 1988.
   
   [2] Cerf, V., "Report of the Second Ad Hoc Network Management Review
       Group", RFC 1109, NRI, August 1989.
   
   [3] Rose M., and K. McCloghrie, "Structure and Identification of
       Management Information for TCP/IP-based internets", RFC 1155,
       Performance Systems International, Hughes LAN Systems, May 1990.
   
   [4] McCloghrie K., and M. Rose, "Management Information Base for
       Network Management of TCP/IP-based internets", RFC 1156, Hughes
       LAN Systems, Performance Systems International, May 1990.
   
   [5] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple
       Network Management Protocol", RFC 1157, SNMP Research,
       Performance Systems International, Performance Systems
       International, MIT Laboratory for Computer Science, May 1990.
   
   [6] McCloghrie K., and M. Rose, Editors, "Management Information Base

for Network Management of TCP/IP-based internets", RFC 1213, Performance Systems International, March 1991.

   [7] Information processing systems - Open Systems Interconnection -
       Specification of Abstract Syntax Notation One (ASN.1),
       International Organization for Standardization, International
       Standard 8824, December 1987.
   
   [8] Information processing systems - Open Systems Interconnection -
       Specification of Basic Encoding Rules for Abstract Notation One
       (ASN.1), International Organization for Standardization,
       International Standard 8825, December 1987.
   
   [9] Rose, M., and K. McCloghrie, Editors, "Concise MIB Definitions",
       RFC 1212, Performance Systems International, Hughes LAN Systems,
       March 1991.
  
  [10] Rose, M., Editor, "A Convention for Defining Traps for use with
       the SNMP", RFC 1215, Performance Systems International, March
       1991.
  
  [11] Lougheed, K., and Y. Rekhter, "A Border Gateway Protocol 3 (BGP-
       3)", RFC 1267, cisco Systems, T.J. Watson Research Center, IBM
       Corp., October 1991.
  
  [12] Rekhter, Y., and P. Gross, Editors, "Application of the Border
       Gateway Protocol in the Internet", RFC 1268, T.J. Watson Research
       Center, IBM Corp., ANS, October 1991.

8. Security Considerations

Security issues are not discussed in this memo.

Authors' Addresses

Steven Willis
Wellfleet Communications Inc.
15 Crosby Drive
Bedford, MA 01730

   Phone: (617) 275-2400
   Email: swillis@wellfleet.com

John Burruss
Wellfleet Communications Inc.
15 Crosby Drive
Bedford, MA 01730

   Phone: (617) 275-2400
   Email: jburruss@wellfleet.com