Draft Entity MIB Extensions September 1997 Entity MIB Extensions for Persistent Component Identification 18 September 1997 Andy Bierman Cisco Systems Inc. abierman@cisco.com Keith McCloghrie Cisco Systems Inc. kzm@cisco.com Status of this Memo This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet- Drafts as reference material or to cite them other than as ``work in progress.'' To learn the current status of any Internet-Draft, please check the ``1id-abstracts.txt'' listing contained in the Internet- Drafts Shadow Directories on ds.internic.net (US East Coast), nic.nordu.net (Europe), ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific Rim). 1. Introduction This memo defines an experimental portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, it describes managed objects used for managing physical topology identification and discovery. Bierman/McCloghrie Expires March 1998 [Page 1] Draft Entity MIB Extensions September 1997 2. The SNMP Network Management Framework The SNMP Network Management Framework presently consists of three major components. They are: o the SMI, described in RFC 1902 [1], - the mechanisms used for describing and naming objects for the purpose of management. o the MIB-II, STD 17, RFC 1213 [2], - the core set of managed objects for the Internet suite of protocols. o the protocol, RFC 1157 [6] and/or RFC 1905 [4], - the protocol for accessing managed information. Textual conventions are defined in RFC 1903 [3], and conformance statements are defined in RFC 1904 [5]. The Framework permits new objects to be defined for the purpose of experimentation and evaluation. This memo specifies a MIB module that is compliant to the SNMPv2 SMI. A semantically identical MIB conforming to the SNMPv1 SMI can be produced through the appropriate translation. 2.1. Object Definitions 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) defined in the SMI. In particular, each object type is named by an OBJECT IDENTIFIER, an administratively assigned name. 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 descriptor, to refer to the object type. 3. Overview There is a need for a standardized way of providing non-volatile, administratively assigned identifiers for physical components represented with the Entity MIB [7]. This document defines extensions to the Entity MIB to address this need. Bierman/McCloghrie Expires March 1998 [Page 2] Draft Entity MIB Extensions September 1997 4. Entity MIB Extensions 4.1. MIB Structure The Entity Extensions MIB contains a single group: - Entity Physical Extensions Group 4.1.1. Entity Physical Extensions Group This group contains a single table, called the entPhysicalXTable, which augments the entPhysicalTable. Each entPhysicalXEntry provides a writable string object, 'entPhysicalAlias', which can be used by an NMS as a non-volatile 'alias' (or label) for the physical component. The entPhysicalAlias object is different from the ifAlias version in several ways: - SnmpAdminString SYNTAX The Interfaces MIB [8] version is defined as a DisplayString [3]. The Entity MIB [7] version is defined as an SnmpAdminString [9]. - SIZE (0..32) The maximum length of the entPhysicalAlias string is half that of the ifAlias object. - MIN-ACCESS Maintaining a non-volatile string for every physical component represented in the entPhysicalTable can be costly and unnecessary. An agent may choose to algorithmically generate entPhysicalAlias strings for particular entries (based on the entPhysicalClass value). 4.2. Definitions ENTITY-EXTENSIONS-MIB DEFINITIONS ::= BEGIN IMPORTS MODULE-IDENTITY, OBJECT-TYPE FROM SNMPv2-SMI MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF SnmpAdminString Bierman/McCloghrie Expires March 1998 [Page 3] Draft Entity MIB Extensions September 1997 FROM SNMP-FRAMEWORK-MIB entPhysicalEntry, entityMIBObjects, entityCompliances, entityGroups, entityPhysicalGroup FROM ENTITY-MIB; entityXMIB MODULE-IDENTITY LAST-UPDATED "9709150000Z" ORGANIZATION "IETF Entity MIB Working Group" CONTACT-INFO "Andy Bierman Cisco Systems Inc. 170 West Tasman Drive San Jose, CA 95134 408-527-3711 abierman@cisco.com Keith McCloghrie Cisco Systems Inc. 170 West Tasman Drive San Jose, CA 95134 408-526-5260 kzm@cisco.com" DESCRIPTION "The extension MIB module for physical entity information." ::= { experimental xx } -- *********************************************************** -- -- E N T I T Y P H Y S I C A L E X T E N S I O N S -- -- *********************************************************** -- entPhysicalTable extensions entityPhysicalX OBJECT IDENTIFIER ::= { entityMIBObjects 5 } entPhysicalXTable OBJECT-TYPE SYNTAX SEQUENCE OF EntPhysicalXEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "This table contains one row per physical element represented in the entPhysicalTable." ::= { entityPhysicalX 1 } Bierman/McCloghrie Expires March 1998 [Page 4] Draft Entity MIB Extensions September 1997 entPhysicalXEntry OBJECT-TYPE SYNTAX EntPhysicalXEntry MAX-ACCESS not-accessible STATUS current DESCRIPTION "Information about a particular physical entity." AUGMENTS { entPhysicalEntry } ::= { entPhysicalXTable 1 } EntPhysicalXEntry ::= SEQUENCE { entPhysicalAlias SnmpAdminString } entPhysicalAlias OBJECT-TYPE SYNTAX SnmpAdminString (SIZE (0..32)) MAX-ACCESS read-write STATUS current DESCRIPTION "This object is an 'alias' name for the physical entity as specified by a network manager, and provides a non-volatile 'handle' for the physical entity. On the first instantiation of an physical entity, the value of entPhysicalAlias associated with that entity is set to the zero-length string. An agent may instead choose to set the value to a locally unique default value instead of a zero-length string. If write access is implemented for an instance of entPhysicalAlias, and a value is written into the instance, the agent must retain the supplied value in the entPhysicalAlias instance associated with the same physical entity for as long as that entity remains instantiated, including across all re-initializations/reboots of the network management system, including those which result in a change of the physical entity's entPhysicalIndex value." ::= { entPhysicalXEntry 1 } -- conformance information -- compliance statements entityXCompliance MODULE-COMPLIANCE STATUS current DESCRIPTION "The compliance statement for SNMP entities which implement Bierman/McCloghrie Expires March 1998 [Page 5] Draft Entity MIB Extensions September 1997 the entPhysicalXTable Entity MIB extension." MODULE -- this module MANDATORY-GROUPS { entityPhysicalGroup, entityPhysicalXGroup } OBJECT entPhysicalAlias MIN-ACCESS read-only DESCRIPTION "Write access is required if the associated entPhysicalClass value is equal to 'chassis(3)'. Otherwise, write access is not required." ::= { entityCompliances 2 } -- MIB groupings entityPhysicalXGroup OBJECT-GROUP OBJECTS { entPhysicalAlias } STATUS current DESCRIPTION "The collection of objects which are used to represent extended physical component information for which a single agent provides management information." ::= { entityGroups 5 } END Bierman/McCloghrie Expires March 1998 [Page 6] Draft Entity MIB Extensions September 1997 5. References [1] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Structure of Management Information for version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1902, January 1996. [2] McCloghrie, K., and M. Rose, Editors, "Management Information Base for Network Management of TCP/IP-based internets: MIB-II", STD 17, RFC 1213, Hughes LAN Systems, Performance Systems International, March 1991. [3] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Textual Conventions for version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1903, January 1996. [4] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Protocol Operations for version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1905, January 1996. [5] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Conformance Statements for version 2 of the Simple Network Management Protocol (SNMPv2)", RFC 1904, January 1996. [6] Case, J., M. Fedor, M. Schoffstall, J. Davin, "Simple Network Management Protocol", RFC 1157, SNMP Research, Performance Systems International, MIT Laboratory for Computer Science, May 1990. [7] McCloghrie, K., Bierman, A., "Entity MIB using SMIv2", RFC 2037, Cisco Systems, October 1996. [8] McCloghrie, K., and Kastenholtz, F., "Interfaces Group Evolution", RFC 1573, Hughes LAN Systems, FTP Software, January 1994. [9] Harrington D., Wijnen, A., "An Architecture for Describing SNMP Management Frameworks", draft-ietf-snmpv3-next-gen-arch-04.txt, Cabletron Systems, IBM T.J. Watson Research, August 1997. Bierman/McCloghrie Expires March 1998 [Page 7] Draft Entity MIB Extensions September 1997 6. Security Considerations No additional security concerns are introduced due to implementation of this MIB module. Refer to RFC 2037 [7] for information on any security issues related to the Entity MIB. 7. Author's Address Andy Bierman Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134 Phone: 408-527-3711 Email: abierman@cisco.com Keith McCloghrie Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134 Phone: 408-526-5260 Email: kzm@cisco.com Bierman/McCloghrie Expires March 1998 [Page 8] Draft Entity MIB Extensions September 1997 Table of Contents 1 Introduction .................................................... 1 2 The SNMP Network Management Framework ........................... 2 2.1 Object Definitions ............................................ 2 3 Overview ........................................................ 2 4 Entity MIB Extensions ........................................... 3 4.1 MIB Structure ................................................. 3 4.1.1 Entity Physical Extensions Group ............................ 3 4.2 Definitions ................................................... 3 5 References ...................................................... 7 6 Security Considerations ......................................... 8 7 Author's Address ................................................ 8 Bierman/McCloghrie Expires March 1998 [Page 9]