Network Working Group S. Willis INTERNET DRAFT J. Burruss Wellfleet Communications Inc. J. Chu IBM Corp December 1992 Definitions of Managed Objects for the Border Gateway Protocol (Version 4) Status of this Memo This memo is an extension to the SNMP MIB. It specifies an IAB standards track protocol for the Internet community, and requests discussion and suggestions for improvements. The origin of this memo is from RFC 1269 "Definitions of Managed Objects for the Board Gateway Protocol (Version 3)" written by the first two authors of this memo. 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. Expiration Date June 1993 [Page 1] - 2 - 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]. Expiration Date June 1993 [Page 2] - 3 - 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 RFCxxxx-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; Expiration Date June 1993 [Page 3] - 4 - -- 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 Expiration Date June 1993 [Page 4] - 5 - 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, bgpPeerFsmEstablishedTransitions Expiration Date June 1993 [Page 5] - 6 - Counter } 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 { stop(1), start(2) } 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 } Expiration Date June 1993 [Page 6] - 7 - 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 Expiration Date June 1993 [Page 7] - 8 - 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 Expiration Date June 1993 [Page 8] - 9 - 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 } bgpPeerFsmEstablishedTransitions OBJECT-TYPE SYNTAX Counter ACCESS read-only STATUS mandatory DESCRIPTION "The total number of times the BGP FSM transitioned intto the established state." ::= { bgpPeerEntry 15 } 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 running BGP version 3 or less." ::= { bgp 5 } Expiration Date June 1993 [Page 9] - 10 - 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 Expiration Date June 1993 [Page 10] - 11 - 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 } Expiration Date June 1993 [Page 11] - 12 - bgp4RcvdPathAttrTable OBJECT-TYPE SYNTAX SEQUENCE OF Bgp4PathAttrEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "The BGP-4 Received Path Attribute Table contains information about paths to destination networks received by all BGP4 peers." ::= { bgp 6 } bgp4PathAttrEntry OBJECT-TYPE SYNTAX Bgp4PathAttrEntry ACCESS not-accessible STATUS mandatory DESCRIPTION "Information about a path to a network." INDEX { bgp4PathAttrPeer, bgp4PathAttrIpAddrPrefixLen, bgp4PathAttrIpAddrPrefix } ::= { bgp4RcvdPathAttrTable 1 } Bgp4PathAttrEntry ::= SEQUENCE { bgp4PathAttrPeer IpAddress, bgp4PathAttrIpAddrPrefixLen INTEGER, bgp4PathAttrIpAddrPrefix OCTET STRING, bgp4PathAttrOrigin INTEGER, bgp4PathAttrASPathSegment OCTET STRING, bgp4PathAttrNextHop IpAddress, bgp4PathAttrMultiExitDisc INTEGER, bgp4PathAttrLocalPref INTEGER, bgp4PathAttrAtomicAggregate INTEGER, bgp4PathAttrAggregator Expiration Date June 1993 [Page 12] - 13 - INTEGER } bgp4PathAttrPeer OBJECT-TYPE SYNTAX IpAddress ACCESS read-only STATUS mandatory DESCRIPTION "The IP address of the peer where the path information was learned." ::= { bgp4PathAttrEntry 1 } bgp4PathAttrIpAddrPrefixLen OBJECT-TYPE SYNTAX INTEGER (0..255) ACCESS read-only STATUS mandatory DESCRIPTION "Length in bits of the IP address prefix in the Network Layer Reachability Information field." ::= { bgp4PathAttrEntry 2 } bgp4PathAttrIpAddrPrefix OBJECT-TYPE SYNTAX OCTET STRING ACCESS read-only STATUS mandatory DESCRIPTION "An IP address prefix in the Network Layer Reachability Information field. This string contains as many octets as necessary to hold a prefix of the length specified by bgp4PathAttrIpAddrPrefixLen. Any bits beyond the length specified by bgp4PathAttrIpAddrPrefixLen are zeroed." ::= { bgp4PathAttrEntry 3 } bgp4PathAttrOrigin 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 Expiration Date June 1993 [Page 13] - 14 - information." ::= { bgp4PathAttrEntry 4 } bgp4PathAttrASPathSegment OBJECT-TYPE SYNTAX OCTET STRING ACCESS read-only STATUS mandatory DESCRIPTION "The sequence of AS path segments. Each AS path segment is represented by a triple . The type is a 1-octet field which has two possible values: 1 AS_SET: unordered set of ASs a route in the UPDATE message has traversed 2 AS_SEQUENCE: ordered set of ASs a route in the UPDATE message has traversed. The length is a 1-octet field containing the number of ASs in the value field. The value field contains one or more AS numbers, each AS is represented in the octet string as a pair of octets according to the following algorithm: first-byte-of-pair = ASNumber / 256; second-byte-of-pair = ASNumber & 255;" ::= { bgp4PathAttrEntry 5 } bgp4PathAttrNextHop OBJECT-TYPE SYNTAX IpAddress ACCESS read-only STATUS mandatory DESCRIPTION "The address of the border router that should be used for the destination network." ::= { bgp4PathAttrEntry 6 } bgp4PathAttrMultiExitDisc OBJECT-TYPE SYNTAX INTEGER (0..255) ACCESS read-only Expiration Date June 1993 [Page 14] - 15 - STATUS mandatory DESCRIPTION "This metric is used to discriminate between multiple exit points to an adjacent autonomous system." ::= { bgp4PathAttrEntry 7 } bgp4PathAttrLocalPref OBJECT-TYPE SYNTAX INTEGER (0..255) ACCESS read-only STATUS mandatory DESCRIPTION "The originating BGP4 speaker's degree of preference for an advertised route." ::= { bgp4PathAttrEntry 8 } bgp4PathAttrAtomicAggregate OBJECT-TYPE SYNTAX INTEGER { less-specific-route-not-selected(1), less-specific-route-selected(2) } ACCESS read-only STATUS mandatory DESCRIPTION "Whether or not the local system has selected a less specific route without selecting a more specific route." ::= { bgp4PathAttrEntry 9 } bgp4PathAttrAggregator OBJECT-TYPE SYNTAX INTEGER (0..65535) ACCESS read-only STATUS mandatory DESCRIPTION "The AS number of the last BGP4 speaker that performed route aggregation. " ::= { bgp4PathAttrEntry 10 } bgpEstablished TRAP-TYPE ENTERPRISE { bgp } VARIABLES { bgpPeerRemoteAddr, bgpPeerLastError, bgpPeerState } Expiration Date June 1993 [Page 15] - 16 - 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, ANS Jeff Honig, Cornell Theory Center Marshall T. Rose, PSI, Inc. Dennis Ferguson, ANS Mike Mathis, PSC John Krawczyk, Wellfleet Communications Inc. Curtis Villamizar, ANS 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 Expiration Date June 1993 [Page 16] - 17 - 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] Rekhter, Y., and Li, T., "A Border Gateway Protocol 4 (BGP-4)", Internet Draft, T.J. Watson Research Center, IBM Corp., cisco Systems, June 1992. [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. Expiration Date June 1993 [Page 17] - 18 - 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 John Chu IBM Corp. P.O.Box 218 Yorktown Heights, NY 10598 Phone: (914) 945-3156 Email: jychu@watson.ibm.com Expiration Date June 1993 [Page 18]