diff options
Diffstat (limited to 'doc/rfc/rfc2856.txt')
-rw-r--r-- | doc/rfc/rfc2856.txt | 563 |
1 files changed, 563 insertions, 0 deletions
diff --git a/doc/rfc/rfc2856.txt b/doc/rfc/rfc2856.txt new file mode 100644 index 0000000..52f8a60 --- /dev/null +++ b/doc/rfc/rfc2856.txt @@ -0,0 +1,563 @@ + + + + + + +Network Working Group A. Bierman +Request for Comments: 2856 K. McCloghrie +Category: Standards Track Cisco Systems, Inc. + R. Presuhn + BMC Software, Inc. + June 2000 + + + Textual Conventions for Additional High Capacity Data Types + +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 + + This memo specifies new textual conventions for additional high + capacity data types, intended for SNMP implementations which already + support the Counter64 data type. The definitions contained in this + document represent a short term solution which may be deprecated in + the future. + +Table of Contents + + 1 The SNMP Management Framework ................................. 2 + 2 Overview ...................................................... 3 + 2.1 Short Term and Long Term Objectives ......................... 3 + 2.2 Limitations of the Textual Convention Approach .............. 3 + 3 New Textual Conventions ....................................... 4 + 3.1 CounterBasedGauge64 ......................................... 4 + 3.2 ZeroBasedCounter64 .......................................... 4 + 4 Definitions ................................................... 4 + 5 Intellectual Property ......................................... 7 + 6 References .................................................... 7 + 7 Security Considerations ....................................... 9 + 8 Authors' Addresses ............................................ 9 + 9 Full Copyright Statement ...................................... 10 + + + + + + +Bierman, et al. Standards Track [Page 1] + +RFC 2856 High Capacity Data Types June 2000 + + +1. The SNMP Management Framework + + The SNMP Management Framework presently consists of five major + components: + + o An overall architecture, described in RFC 2571 [RFC2571]. + + o Mechanisms for describing and naming objects and events for the + purpose of management. The first version of this Structure of + Management Information (SMI) is called SMIv1 and described in STD + 16, RFC 1155 [RFC1155], STD 16, RFC 1212 [RFC1212] and RFC 1215 + [RFC1215]. The second version, called SMIv2, is described in STD + 58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, + RFC 2580 [RFC2580]. + + o Message protocols for transferring management information. The + first version of the SNMP message protocol is called SNMPv1 and + described in STD 15, RFC 1157 [RFC1157]. A second version of the + SNMP message protocol, which is not an Internet standards track + protocol, is called SNMPv2c and described in RFC 1901 [RFC1901] + and RFC 1906 [RFC1906]. The third version of the message + protocol is called SNMPv3 and described in RFC 1906 [RFC1906], + RFC 2572 [RFC2572] and RFC 2574 [RFC2574]. + + o Protocol operations for accessing management information. The + first set of protocol operations and associated PDU formats is + described in STD 15, RFC 1157 [RFC1157]. A second set of + protocol operations and associated PDU formats is described in + RFC 1905 [RFC1905]. + + o A set of fundamental applications described in RFC 2573 [RFC2573] + and the view-based access control mechanism described in RFC 2575 + [RFC2575]. + + A more detailed introduction to the current SNMP Management Framework + can be found in RFC 2570 [RFC2570]. + + Managed objects are accessed via a virtual information store, termed + the Management Information Base or MIB. Objects in the MIB are + defined using the mechanisms defined in the SMI. + + This memo specifies a MIB module that is compliant to the SMIv2. The + textual conventions defined in this MIB module cannot be translated + to SMIv1 since the Counter64 type does not exist in SMIv1. + + + + + + + +Bierman, et al. Standards Track [Page 2] + +RFC 2856 High Capacity Data Types June 2000 + + +2. Overview + + The Structure of Management Information [RFC2578] does not explicitly + address the question of how to represent integer objects other than + counters that would require up to 64 bits to provide the necessary + range and precision. There are MIBs in progress targeted for the + standards track, which need such data types. This memo specifies a + short term solution, using textual conventions, to meet these needs. + +2.1. Short Term and Long Term Objectives + + There is an immediate need to provide a Gauge64 data type, similar in + semantics to the Gauge32 data type, in order to support common data + representations such as: + + - a snapshot of a Counter64 at a given moment, e.g., history ring + buffer + + - the difference between two Counter64 values + + There is also an immediate need for a 64-bit zero-based counter type, + similar in semantics to the ZeroBasedCounter32 TC defined in the + RMON-2 MIB [RFC2021]. + + Both of these textual conventions should use a base type of Gauge64 + or Unsigned64, but such a base type is not available. Until such a + base type is defined and deployed, these temporary textual + conventions (which use a base type of Counter64) will be used in MIBs + which require unsigned 64-bit data types. + + In order to be backward compatible with existing implementations of + Counter64, the ASN.1 encoding of unsigned 64-bit data types must be + identical to the encoding of Counter64 objects, i.e., identified by + the [APPLICATION 6] ASN.1 tag. + + Note that the textual conventions defined in this document represent + a limited and short-term solution to the problem. These textual + conventions may be deprecated as a long term solution is defined and + deployed to replace them. A MIB object which uses either of these + textual conventions may also eventually have to be deprecated. + +2.2. Limitations of the Textual Convention Approach + + New unsigned data types with textual conventions based on the + Counter64 tag, instead of a new (or other existing) ASN.1 tag have + some limitations: + + + + + +Bierman, et al. Standards Track [Page 3] + +RFC 2856 High Capacity Data Types June 2000 + + + - The MAX-ACCESS of the TC must be read-only, because the MAX-ACCESS + of the underlying Counter64 type is read-only. + + - No sub-range can be specified on the TC-derived types, because + sub-ranges are not allowed on Counter64 objects. + + - No DEFVAL clause can be specified for the TC-derived types, + because DEFVALs are not allowed on Counter64 objects. + + - The TC-derived types cannot be used in an INDEX clause, because + there is no INDEX clause mapping defined for objects of type + Counter64. + +3. New Textual Conventions + + The following textual conventions are defined to support unsigned + 64-bit data types. + +3.1. CounterBasedGauge64 + + This textual convention defines a 64-bit gauge, but defined with + Counter64 syntax, since no Gauge64 or Unsigned64 base type is + available in SMIv2. + + This TC is used for storing the difference between two Counter64 + values, or simply storing a snapshot of a Counter64 value at a given + moment in time. + +3.2. ZeroBasedCounter64 + + This textual convention defines a 64-bit counter with an initial + value of zero, instead of an arbitrary initial value. + + This TC is used for counter objects in tables which are instantiated + by management application action. + +4. Definitions + + HCNUM-TC DEFINITIONS ::= BEGIN + + IMPORTS + MODULE-IDENTITY, mib-2, Counter64 + FROM SNMPv2-SMI + TEXTUAL-CONVENTION + FROM SNMPv2-TC; + + hcnumTC MODULE-IDENTITY + LAST-UPDATED "200006080000Z" + + + +Bierman, et al. Standards Track [Page 4] + +RFC 2856 High Capacity Data Types June 2000 + + + ORGANIZATION "IETF OPS Area" + CONTACT-INFO + " E-mail: mibs@ops.ietf.org + Subscribe: majordomo@psg.com + with msg body: subscribe mibs + + Andy Bierman + Cisco Systems Inc. + 170 West Tasman Drive + San Jose, CA 95134 USA + +1 408-527-3711 + abierman@cisco.com + + Keith McCloghrie + Cisco Systems Inc. + 170 West Tasman Drive + San Jose, CA 95134 USA + +1 408-526-5260 + kzm@cisco.com + + Randy Presuhn + BMC Software, Inc. + Office 1-3141 + 2141 North First Street + San Jose, California 95131 USA + +1 408 546-1006 + rpresuhn@bmc.com" + DESCRIPTION + "A MIB module containing textual conventions + for high capacity data types. This module + addresses an immediate need for data types not directly + supported in the SMIv2. This short-term solution + is meant to be deprecated as a long-term solution + is deployed." + REVISION "200006080000Z" + DESCRIPTION + "Initial Version of the High Capacity Numbers + MIB module, published as RFC 2856." + ::= { mib-2 78 } + + CounterBasedGauge64 ::= TEXTUAL-CONVENTION + STATUS current + DESCRIPTION + "The CounterBasedGauge64 type represents a non-negative + integer, which may increase or decrease, but shall never + exceed a maximum value, nor fall below a minimum value. The + maximum value can not be greater than 2^64-1 + (18446744073709551615 decimal), and the minimum value can + + + +Bierman, et al. Standards Track [Page 5] + +RFC 2856 High Capacity Data Types June 2000 + + + not be smaller than 0. The value of a CounterBasedGauge64 + has its maximum value whenever the information being modeled + is greater than or equal to its maximum value, and has its + minimum value whenever the information being modeled is + smaller than or equal to its minimum value. If the + information being modeled subsequently decreases below + (increases above) the maximum (minimum) value, the + CounterBasedGauge64 also decreases (increases). + + Note that this TC is not strictly supported in SMIv2, + because the 'always increasing' and 'counter wrap' semantics + associated with the Counter64 base type are not preserved. + It is possible that management applications which rely + solely upon the (Counter64) ASN.1 tag to determine object + semantics will mistakenly operate upon objects of this type + as they would for Counter64 objects. + + This textual convention represents a limited and short-term + solution, and may be deprecated as a long term solution is + defined and deployed to replace it." + SYNTAX Counter64 + + + ZeroBasedCounter64 ::= TEXTUAL-CONVENTION + STATUS current + DESCRIPTION + "This TC describes an object which counts events with the + following semantics: objects of this type will be set to + zero(0) on creation and will thereafter count appropriate + events, wrapping back to zero(0) when the value 2^64 is + reached. + + Provided that an application discovers the new object within + the minimum time to wrap it can use the initial value as a + delta since it last polled the table of which this object is + part. It is important for a management station to be aware + of this minimum time and the actual time between polls, and + to discard data if the actual time is too long or there is + no defined minimum time. + + Typically this TC is used in tables where the INDEX space is + constantly changing and/or the TimeFilter mechanism is in + use. + + Note that this textual convention does not retain all the + semantics of the Counter64 base type. Specifically, a + Counter64 has an arbitrary initial value, but objects + defined with this TC are required to start at the value + + + +Bierman, et al. Standards Track [Page 6] + +RFC 2856 High Capacity Data Types June 2000 + + + zero. This behavior is not likely to have any adverse + effects on management applications which are expecting + Counter64 semantics. + + This textual convention represents a limited and short-term + solution, and may be deprecated as a long term solution is + defined and deployed to replace it." + SYNTAX Counter64 + + END + +5. Intellectual Property + + The IETF takes no position regarding the validity or scope of any + intellectual property or other rights that might be claimed to + pertain to the implementation or use of the technology described in + this document or the extent to which any license under such rights + might or might not be available; neither does it represent that it + has made any effort to identify any such rights. Information on the + IETF's procedures with respect to rights in standards-track and + standards- related documentation can be found in BCP-11. Copies of + claims of rights made available for publication and any assurances of + licenses to be made available, or the result of an attempt made to + obtain a general license or permission for the use of such + proprietary rights by implementors or users of this specification can + be obtained from the IETF Secretariat. + + The IETF invites any interested party to bring to its attention any + copyrights, patents or patent applications, or other proprietary + rights which may cover technology that may be required to practice + this standard. Please address the information to the IETF Executive + Director. + +6. References + + [RFC1155] Rose, M. and K. McCloghrie, "Structure and Identification + of Management Information for TCP/IP-based Internets", + STD 16, RFC 1155, May 1990. + + [RFC1157] Case, J., Fedor, M., Schoffstall, M. and J. Davin, + "Simple Network Management Protocol", STD 15, RFC 1157, + May 1990. + + [RFC1212] Rose, M. and K. McCloghrie, "Concise MIB Definitions", + STD 16, RFC 1212, March 1991. + + [RFC1215] Rose, M., "A Convention for Defining Traps for use with + the SNMP", RFC 1215, March 1991. + + + +Bierman, et al. Standards Track [Page 7] + +RFC 2856 High Capacity Data Types June 2000 + + + [RFC1901] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, + "Introduction to Community-based SNMPv2", RFC 1901, + January 1996. + + [RFC1905] 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. + + [RFC1906] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, + "Transport Mappings for Version 2 of the Simple Network + Management Protocol (SNMPv2)", RFC 1906, January 1996. + + [RFC2021] Waldbusser, S., "Remote Network Monitoring MIB (RMON-2)", + RFC 2021, January 1997. + + [RFC2026] Bradner, S., "The Internet Standards Process -- Revision + 3", BCP 9, RFC 2026, October 1996. + + [RFC2570] Case, J., Mundy, R., Partain, D. and B. Stewart, + "Introduction to Version 3 of the Internet-standard + Network Management Framework", RFC 2570, April 1999. + + [RFC2571] Harrington, D., Presuhn, R. and B. Wijnen, "An + Architecture for Describing SNMP Management Frameworks", + RFC 2571, April 1999. + + [RFC2572] Case, J., Harrington D., Presuhn R. and B. Wijnen, + "Message Processing and Dispatching for the Simple + Network Management Protocol (SNMP)", RFC 2572, April + 1999. + + [RFC2573] Levi, D., Meyer, P. and B. Stewart, "SNMPv3 + Applications", RFC 2573, April 1999. + + [RFC2574] Blumenthal, U. and B. Wijnen, "User-based Security Model + (USM) for version 3 of the Simple Network Management + Protocol (SNMPv3)", RFC 2574, April 1999. + + [RFC2575] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based + Access Control Model (VACM) for the Simple Network + Management Protocol (SNMP)", RFC 2575, April 1999. + + [RFC2578] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., + Rose, M. and S. Waldbusser, "Structure of Management + Information Version 2 (SMIv2)", STD 58, RFC 2578, April + 1999. + + + + + +Bierman, et al. Standards Track [Page 8] + +RFC 2856 High Capacity Data Types June 2000 + + + [RFC2579] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., + Rose, M. and S. Waldbusser, "Textual Conventions for + SMIv2", STD 58, RFC 2579, April 1999. + + [RFC2580] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., + Rose, M. and S. Waldbusser, "Conformance Statements for + SMIv2", STD 58, RFC 2580, April 1999. + +7. Security Considerations + + This module does not define any management objects. Instead, it + defines a set of textual conventions which may be used by other MIB + modules to define management objects. + + Meaningful security considerations can only be written in the modules + that define management objects. + +8. Authors' Addresses + + Andy Bierman + Cisco Systems, Inc. + 170 West Tasman Drive + San Jose, CA 95134 USA + + Phone: +1 408-527-3711 + EMail: abierman@cisco.com + + + Keith McCloghrie + Cisco Systems, Inc. + 170 West Tasman Drive + San Jose, CA 95134 USA + + Phone: +1 408-526-5260 + EMail: kzm@cisco.com + + + Randy Presuhn + BMC Software, Inc. + Office 1-3141 + 2141 North First Street + San Jose, California 95131 USA + + Phone: +1 408 546-1006 + EMail: rpresuhn@bmc.com + + + + + + +Bierman, et al. Standards Track [Page 9] + +RFC 2856 High Capacity Data Types June 2000 + + +9. Full Copyright Statement + + Copyright (C) The Internet Society (2000). All Rights Reserved. + + This document and translations of it may be copied and furnished to + others, and derivative works that comment on or otherwise explain it + or assist in its implementation may be prepared, copied, published + and distributed, in whole or in part, without restriction of any + kind, provided that the above copyright notice and this paragraph are + included on all such copies and derivative works. However, this + document itself may not be modified in any way, such as by removing + the copyright notice or references to the Internet Society or other + Internet organizations, except as needed for the purpose of + developing Internet standards in which case the procedures for + copyrights defined in the Internet Standards process must be + followed, or as required to translate it into languages other than + English. + + The limited permissions granted above are perpetual and will not be + revoked by the Internet Society or its successors or assigns. + + This document and the information contained herein is provided on an + "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING + TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING + BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION + HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF + MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +Acknowledgement + + Funding for the RFC Editor function is currently provided by the + Internet Society. + + + + + + + + + + + + + + + + + + + +Bierman, et al. Standards Track [Page 10] + |