IPFIX Working Group B. Claise Internet-Draft P. Aitken Intended status: Standards Track S. B S Expires: August 29, 2013 Cisco Systems, Inc. J. Schoenwaelder Jacobs University Bremen February 25, 2013 Exporting MIB Variables using the IPFIX Protocol draft-ietf-ipfix-mib-variable-export-02 Abstract This document specifies a way to complement IPFIX Flow Records with Management Information Base (MIB) objects, avoiding the need to define new IPFIX Information Elements for existing Management Information Base objects that are already fully specified. This method requires an extension to the current IPFIX protocol. New Template Set and Options Template Sets are specified to allow the export of Extended Field Specifiers, which may represent IPFIX Information Elements and Simple Network Management Protocol (SNMP) MIB Objects. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on August 29, 2013. Copyright Notice Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Claise, et al. Expires August 29, 2013 [Page 1] Internet-Draft Exporting MIB Variables with IPFIX February 2013 Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Open Issues / To do list . . . . . . . . . . . . . . . . . . . 4 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Motivation and Architectural Model . . . . . . . . . . . . . . 6 4. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 8 5. Extended Records . . . . . . . . . . . . . . . . . . . . . . . 8 5.1. Extended Template Record Format . . . . . . . . . . . . . 8 5.2. Extended Options Template Record Format . . . . . . . . . 10 5.3. Extended Field Specifiers . . . . . . . . . . . . . . . . 11 5.3.1. Standard Field Specifier Format . . . . . . . . . . . 11 5.3.2. Extended Field Specifier Format . . . . . . . . . . . 12 5.3.3. Extended Field Specifier Format for IPFIX Information Elements . . . . . . . . . . . . . . . . . 15 5.3.4. Extended Field Specifier Format for a non-indexed MIB Object . . . . . . . . . . . . . . . . . . . . . . 16 5.3.5. Extended Field Specifier Format for an indexed MIB Object, with a MIB OID as index . . . . . . . . . . . 17 5.3.6. Extended Field Specifier Format for an indexed MIB Object, with an IPFIX Information Element as index . . 20 5.3.7. Extended Field Specifier Format for an indexed MIB Object, with a previous IPFIX Information Element as index . . . . . . . . . . . . . . . . . . . . . . . 24 5.3.8. Extended Field Specifier Format for an Indexed MIB Object, with an IPFIX Information Element for the OID segment identifying the instance . . . . . . . . . 27 5.4. Identifying the SNMP Context . . . . . . . . . . . . . . . 30 5.5. Template Management . . . . . . . . . . . . . . . . . . . 30 6. Example Use Cases . . . . . . . . . . . . . . . . . . . . . . 31 6.1. Without Using the Specifications in this Document . . . . 31 6.2. Non-indexed MIB Object: Established TCP Connections . . . 32 6.3. Enterprise Specific MIB Object: Detailing CPU Load History . . . . . . . . . . . . . . . . . . . . . . . . . 34 6.4. Indexed MIB Object with Two OIDs: The ipIfStatsInForwDatagrams . . . . . . . . . . . . . . . . . 37 6.5. Indexed MIB Object with an IPFIX Information Element: Output Interface Queue Size in PSAMP Packet Report . . . . 39 6.6. Indexed MIB Object with an OID: Output Interface Queue Claise, et al. Expires August 29, 2013 [Page 2] Internet-Draft Exporting MIB Variables with IPFIX February 2013 Size in PSAMP Packet Report . . . . . . . . . . . . . . . 43 6.7. Indexed MIB Objects with a mix of MIB OID and IPFIX Information Element . . . . . . . . . . . . . . . . . . . 46 6.8. Indexed MIB Object with MIBInstanceIdentifier Information Element: ipIfStatsOutOctets . . . . . . . . . 46 6.9. Using MIB Objects as IPFIX Options Scope fields . . . . . 48 6.9.1. Using non-Indexed MIB Objects as Option Scope fields . . . . . . . . . . . . . . . . . . . . . . . . 48 6.9.2. Using Indexed MIB Objects as Option Scope fields . . . 50 6.10. Using MIB Objects with IPFIX Structured Data . . . . . . . 52 6.11. Using IPFIX Structured Data to group the index MIB and indices . . . . . . . . . . . . . . . . . . . . . . . . . 53 7. Configuration Considerations . . . . . . . . . . . . . . . . . 53 8. The Collecting Process's Side . . . . . . . . . . . . . . . . 53 9. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 53 10. Security Considerations . . . . . . . . . . . . . . . . . . . 54 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 54 11.1. New Set IDs . . . . . . . . . . . . . . . . . . . . . . . 54 11.2. New Data Types . . . . . . . . . . . . . . . . . . . . . . 54 11.3. New Information Elements . . . . . . . . . . . . . . . . . 55 11.4. New Extension Types registry . . . . . . . . . . . . . . . 55 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 56 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 56 13.1. Normative References . . . . . . . . . . . . . . . . . . . 56 13.2. Informative References . . . . . . . . . . . . . . . . . . 57 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 57 Claise, et al. Expires August 29, 2013 [Page 3] Internet-Draft Exporting MIB Variables with IPFIX February 2013 1. Open Issues / To do list o Replace RFC5101 references with 5101bis. o Replace RFC5102 references into 5102bis or IANA-IPFIX. o "timestamps, exporters, and other animals" -> see the mailing list. o The value of the MIB OID acting as an index may not be of fixed length and may have no default length, for example the OID can be of type string or type MIB OID. o Some TODO in the XML version: * write section 6.7: "Indexed MIB Objects with a mix of MIB OID and IPFIX Information Element" * write section 6.10: "Using MIB Objects with IPFIX Structured Data" * write section 6.11: "Using IPFIX Structured Data to group the index MIB and indices" o RFC 5610: explain what needs to be updated. o ID to name mappings? -> use this for an example in section 5. o What does this mean? : "(Consider the counter synchronization issue, non-key info should be static)". o (JS) Do we need to add something about the contextEngineID and contextName? Optionally associate context with template via options Could be done with common properties or in a flow record. See section 5.6. However, do we limit all MIB variables in a Template Record to a single context? 3 cases: 1. if a simple SNMP agent, no contextEngineID and contextName, because it's the default 2. the context information is valid for the entire flow record 3. the context information is specific for each IE within the entire flow record question regarding 3.: only one context for an entire flow or can a flow record export MIB OID from different context? (JS): ask the IPFIX mailing list. (BC): ask internally in Cisco Action: Claise, et al. Expires August 29, 2013 [Page 4] Internet-Draft Exporting MIB Variables with IPFIX February 2013 complete the "Identifying the SNMP Context" section o (JS) Inacio's figure: send email to the mailing list. o Unobserved fields could be reported in EFSF format, ie by an "(un)observed" extension. o Tidy up the XML. 2. Introduction There is growing interest in using IPFIX as a push mechanism for exporting management information. Using a push protocol such as IPFIX instead of a polling protocol like SNMP is especially interesting in situations where large chunks of repetitive data need to be exported periodically. While initially targeted at different problems, there is a large parallel between the information transported via IPFIX and SNMP. Furthermore, certain Management Information Base (MIB) objects are highly relevant to flows as they are understood today. For example, in the IPFIX information model [RFC5102], Information Elements coming from the SNMP world have already been specified, e.g., ingressInterface and egressInterface both refer to the ifIndex defined in [RFC2863]. Rather than mapping existing MIB objects to IPFIX Information Elements on a case by case basis, it would be advantageous to enable the export of any existing or future MIB objects as part of an IPFIX Flow Record. This way, the duplication of data models [RFC3444], both as SMI MIB objects and IPFIX Information Elements, out of the same information model [RFC3444] would be avoided. In this document, new Template Sets for Flow Records and Options Records are specified to allow Templates to contain any combination of fields defined by traditional IPFIX Information Element(s) and/or MIB Object Identifier(s). The MIB Object Identifiers can reference either non-indexed or indexed MIB object(s). Enterprise-specific MIB Object Identifiers are also supported. When an indexed MIB object is exported, a method to identify how that MIB object is indexed is specified so that the full meaning of the information being exported can be conveyed. The specification encompasses the different index types for the MIB Objects Identifier: indexed by one or multiple MIB variable(s), indexed by one or multiple IPFIX Information Element(s), indexed by a mix of MIB variable(s) and IPFIX Information Element(s). A set of example use Claise, et al. Expires August 29, 2013 [Page 5] Internet-Draft Exporting MIB Variables with IPFIX February 2013 cases illustrates how these specifications can be used. Some Exporters may not have the knowledge to convey the full information on how the MIB objects being exported are indexed. They may not know the index count and/or the OID's of the objects that are used to index a MIB object. In such cases the Exporter can send the the values of the index OID's identifying the instance of the object being exported as one string that conveys the instance identifier part of an object being exported. The Collecting Process may know how a MIB object is indexed by some other means, for example, it could compile this information from the MIB Module that defines exported MIB object or the Collecting Process could be hardcoded with this information for a pre-defined set of MIB objects that it is interested in. An example use case is used to illustrate this mechanism. 3. Motivation and Architectural Model Most Flow Records contain the ingressInterface and/or the egressInterface Information Element. These Information Elements carry an ifIndex value, a MIB object defined in [RFC2863]. In order to retrieve additional information about the identified interface, a Collector could simply poll relevant objects from the device running the Exporter via SNMP, however, that approach has several problems: o It requires implementing a mediation function between two data models, i.e., MIB objects and IPFIX Information Elements. o Confirming the validity of simple mappings (e.g., ifIndex to ifName) requires to either check on a regular basis that the Exporter's network management system did not reload, or imposing ifIndex persistence across an Exporter's reload. o Synchronization problems occur since counters carried in Flow Records and counters carried in SNMP messages are retrieved from the Exporter at different points in time and thus can't be correlated. In the best case, assuming very tight integration of an IPFIX Collector with and SNMP polling engine, SNMP data is retrieved shortly after Data Records have been received, which implies the sum of the active or inactive timeouts (if not null) plus the time to export the Flow Record to the Collector. If, however, the SNMP data is retrieved by a generic Network Management Station (NMS) polling interface statistics, then the time lag between IPFIX counters and SNMP counters can be significant. The intended scope of this work is the addition of MIB variable(s) to Claise, et al. Expires August 29, 2013 [Page 6] Internet-Draft Exporting MIB Variables with IPFIX February 2013 IPFIX Information Elements in Flow Records, in order to complement the Flow Records with useful and already standardized information. More specifically, the case of an existing Template Record, which needed to be augmented with some MIB variables whose index was already present in the Template Record as an IPFIX Information Element: typically, a 7-tuple Flow Record containing the ingressInterface Information Element, augmented by interface counters [RFC2863], which are indexed by the respective ingressInterface values in the Flow Records. The intended goal of this work is not a replacement of SNMP notifications, even if the specifications in this document could potentially allow this. Since IPFIX is a push mechanism, initiated from the Exporter with no acknowledgment method, this specification does not provide the ability to execute configuration changes. The Distributed Management Expression MIB [RFC2982], which is a mechanism to create new MIB variables based on the content of existing ones, could also be advantageous in this context of this specification. Indeed, newly created MIB object (for example, the link utilization MIB variable), created with the Distributed Management Expression MIB [RFC2982] could nicely complement Flow Records. Another advantage of exporting MIB objects via IPFIX is that IPFIX would benefit from an extended series of types to be exported. The simple and application-wide data types specified in SMIv2 [RFC2578], along with a new textual conventions, can be exported within IPFIX and then decoded in the Collector. +------+ +-------+ +.........+ +.....+ | SNMP | | IPFIX | : NETCONF : : CLI : +------+ +-------+ +.........+ +.....+ | | | | +--------------------------------------------+ | Instrumentation (specified in MIB modules) | +--------------------------------------------+ Figure 1: Architectural Model The overall architectural model is depicted in Figure 1. The IPFIX Exporter accesses the device's instrumentation, which follows the specifications contained in MIB modules. Other management interfaces such as NETCONF or the device's Command Line Interface (CLI) may provide access to the same instrumentation. Claise, et al. Expires August 29, 2013 [Page 7] Internet-Draft Exporting MIB Variables with IPFIX February 2013 4. Terminology IPFIX-specific terminology (Information Element, Template, Template Record, Options Template Record, Template Set, Collector, Exporter, Flow Record, etc.) used in this document is defined in Section 2 of [RFC5101]. As in [RFC5101], these IPFIX-specific terms have the first letter of a word capitalized. This document prefers the more generic term "Data Record" as opposed to "Flow Record" as this specification allows the export of MIB objects. MIB Object Identifier (MIB OID) An ASCII character sequence of decimal non-negative sub- identifier values. Each sub-identifier value MUST NOT exceed 2^32-1 (4294967295) and MUST NOT have leading zeros. Sub- identifiers are separated by single dots and without any intermediate whitespace. MIB Object Identifier Information Element An IPFIX Information Element ("mibObjectIdentifier") that denotes that a MIB Object Identifier is exported in the (Options) Data Record. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 5. Extended Records Extended Template and Option Template Records contain Extended Field Specifiers, which are required to export data defined by MIB Object Identifiers. The new Template Set and Option Template Set required for these extended Template Record Formats are defined in Section 11.1. 5.1. Extended Template Record Format The format of the Extended Template Record is shown in Figure 2. It consists of a Template Record Header followed by zero or more Extended Field Specifiers, which may identify any combination of IANA-assigned and/or enterprise-specific Extended Information Elements. Claise, et al. Expires August 29, 2013 [Page 8] Internet-Draft Exporting MIB Variables with IPFIX February 2013 +---------------------------------------------------+ | Template Record Header | +---------------------------------------------------+ | Extended Field Specifier | +---------------------------------------------------+ | Extended Field Specifier | +---------------------------------------------------+ ... +---------------------------------------------------+ | Extended Field Specifier | +---------------------------------------------------+ Figure 2: Extended Template Record Format The format of the Template Record Header is shown in Figure 3. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID (> 255) | Field Count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Template Record Header Format Where: Template ID Template ID of this Template Record. This value is greater than 255. Field Count Number of all fields in this Template Record. At this level of detail the layout of the Template Record Format as specified in [RFC5101], and the Extended Template Record Format are identical. It is only the structure of the Extended Field Specifiers that is different (see Section 5.3). Due to this difference, Extended Template Records MUST NOT be exported in IPFIX Set ID 2. Extended Template Records MUST be exported in a new IPFIX Set using Set ID TBD1 defined in Section 11.1. Claise, et al. Expires August 29, 2013 [Page 9] Internet-Draft Exporting MIB Variables with IPFIX February 2013 5.2. Extended Options Template Record Format The format of the Extended Options Template Record is shown in Figure 4. It consists of an Options Template Record Header followed by zero or more Extended Field Specifiers, which MAY be scope fields. These may identify any combination of IANA-assigned and/or enterprise-specific Extended Information Elements. +---------------------------------------------------+ | Options Template Record Header | +---------------------------------------------------+ | Extended Field Specifier | +---------------------------------------------------+ | Extended Field Specifier | +---------------------------------------------------+ ... +---------------------------------------------------+ | Extended Field Specifier | +---------------------------------------------------+ Figure 4: Extended Options Template Record Format The format of the Extended Options Template Record Header is shown in Figure 5. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID (> 255) | Field Count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope Field Count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5: Options Template Record Header Format Where: Template ID Template ID of this Template Record. This value is greater than 255. Field Count Number of all fields in this Template Record, including the Scope Fields. Claise, et al. Expires August 29, 2013 [Page 10] Internet-Draft Exporting MIB Variables with IPFIX February 2013 Scope Field Count Number of scope fields in this Options Template Record. The Scope Fields are normal Fields except that they are interpreted as Scope at the Collector. The Scope Field Count MUST NOT be zero for an Options Template Record. As with the Template Record Format, the only difference between the standard Options Template Record Format as defined in [RFC5101] and the Extended Template Options Record Format is the structure of the Extended Field Specifiers (see Section 5.3). Due to this difference, Extended Option Template Records MUST NOT be exported in IPFIX Set ID 3. Extended Option Template Records MUST be exported in a new IPFIX Set using Set ID TBD2 defined in Section 11.1. Extended Fields - including both indexed and non-indexed MIB objects - may be used as scope fields in an IPFIX Options Template Record. When indexed MIB objects are used, the index information is not included in the Scope Field Count, since the size of the index information is already specified in the Extended Field (see Section 5.3.5). Examples are given in Section 6.9. 5.3. Extended Field Specifiers This section specifies how the Field Specifier format in [RFC5101] is extended to allow fields to be defined using a specified MIB object. The Field Specifier formats are shown in Figure 6 to Figure 15 below. 5.3.1. Standard Field Specifier Format The Field Specifier format in Figure 6, along with the associated definitions, has been copied from [RFC5101], for an easier comparison with the Extended Field Specifier Formats in Figure 7 through Figure 15. When exporting an IANA-assigned and/or enterprise-specific IPFIX Information Element identifier in IPFIX per [RFC5101] (ie, using Set ID 2 or Set ID 3) the Field Specifier Format is as shown in Figure 6. Claise, et al. Expires August 29, 2013 [Page 11] Internet-Draft Exporting MIB Variables with IPFIX February 2013 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |E| Information Element ident. | Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Enterprise Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6: Standard Field Specifier format Where: E Enterprise bit. This is the first bit of the Field Specifier. If this bit is zero, the Information Element Identifier identifies an IETF specified Information Element, and the four octet Enterprise Number field MUST NOT be present. If this bit is one, the Information Element identifier identifies an enterprise-specific Information Element, and the Enterprise Number filed MUST be present. Information Element identifier A numeric value that represents the type of the Information Element. Refer to [RFC5102]. Field Length The length of the corresponding encoded Information Element, in octets. Refer to [RFC5102]. The field length may be smaller than the definition in [RFC5102] if reduced size encoding is used. The value 65535 is reserved for variable length Information Elements. Enterprise Number IANA enterprise number [PEN] of the authority defining the Information Element identifier in this Template Record. 5.3.2. Extended Field Specifier Format When exporting an IANA-assigned and/or enterprise-specific IPFIX Extended Information Element identifier (ie, using Set ID TBD1 or Set ID TBD2), the Extended Field Specifier format MUST be used. The Extended Field Specifier format consists of a Standard Field Specifier, followed by zero or more extensions. Claise, et al. Expires August 29, 2013 [Page 12] Internet-Draft Exporting MIB Variables with IPFIX February 2013 Each extension consists of a Type, Data Length, Info Length, and Info. The Type indicates which extension it is. The Data Length allows the extension to contribute additional information in Data Records, eg an index value. The Info Length indicates how long the Info field is. The Info field carries one-time additional information, eg a MIB OID. The Extended Field Specifier format is shown in Figure 7. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |E| Information Element ident. | Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Enterprise Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length | Extension 1 Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Data Length | Extension 1 Info Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 2 Type | Extension 2 Data Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 2 Info Length | Extension 2 Info ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension N Type | Extension N Data Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension N Info Length | Extension N Info ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... Extension N Info | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7: Extended Field Specifier format Where: E Enterprise bit. This is the first bit of the Field Specifier. If this bit is zero, the Information Element Identifier identifies an IETF specified Information Element, and the four octet Enterprise Number field MUST NOT be present. If this bit is one, the Information Element identifier identifies an enterprise-specific Information Element, and the Enterprise Number filed MUST be present. Claise, et al. Expires August 29, 2013 [Page 13] Internet-Draft Exporting MIB Variables with IPFIX February 2013 Information Element identifier A numeric value that represents the type of the Information Element. Refer to [RFC5102]. Field Length The length of the corresponding encoded Information Element, in octets, not including any extension data. Refer to [RFC5102]. The field length may be smaller than the definition in [RFC5102] if reduced size encoding is used. The value 65535 is reserved for variable length Information Elements. Enterprise Number IANA enterprise number [PEN] of the authority defining the Information Element identifier in this Template Record. Extension Length The Extension Length indicates the number of extension octets (ie the amount of data to the end of the Extended Field Specifier), including all the Extension Type, Extension Length, Extension Info Length, and Extension Info octets, not including the Extension Length itself. This may be Zero or more. A collector can reach the end of the Extended Field Specifier by moving forward this number of octets. Extension N Type The type of extension N, from the extension types in Table 1. Extension N Data Length The number of additional octets which Extension N contributes to Data Records. This may be zero or more, and may be encoded using IPFIX variable-length encoding per section 7 of [RFC5102]. Extension N Info Length The length of the following "Extension N Info" field, if any. This may be zero or more. Extension N Info Additional information associated with extension N. Claise, et al. Expires August 29, 2013 [Page 14] Internet-Draft Exporting MIB Variables with IPFIX February 2013 The Extension Types are defined in Table 1: +------+--------------+---------------------------------------------+ | Type | Extension | Extension Description | | | Name | | +------+--------------+---------------------------------------------+ | 0 | Reserved | Reserved | +------+--------------+---------------------------------------------+ | 1 | MIB OID | The extension contains a MIB Object | | | | Identifier. | +------+--------------+---------------------------------------------+ | 2 | MIB index | The extension contains an additional MIB as | | | | an index. | +------+--------------+---------------------------------------------+ | 3 | IE index | The extension contains an additional IPFIX | | | | Information Element as an index. | +------+--------------+---------------------------------------------+ | 4 | previousIE | The extension contains the | | | index | informationElementIndex of a previous | | | | Information Element in the Flow Record as | | | | an index. | +------+--------------+---------------------------------------------+ | 5 | MIB Instance | The extension contains a MIB Instance | | | Identifier | Identifier as an index. | | | index | | +------+--------------+---------------------------------------------+ Table 1: Extension Types 5.3.3. Extended Field Specifier Format for IPFIX Information Elements Since IPFIX Information Elements - whether IANA standard or enterprise-specific - contain no extensions, they may be exported using the Extended Field Specifier format with the "Extension Length" set to zero, as shown in Figure 8: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |E| Information Element ident. | Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Enterprise Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 8: Extended Field Specifier format for IPFIX Information Elements Claise, et al. Expires August 29, 2013 [Page 15] Internet-Draft Exporting MIB Variables with IPFIX February 2013 5.3.4. Extended Field Specifier Format for a non-indexed MIB Object Non-indexed MIB OIDs are exported using the Extended Field Specifier format with a single extension which contains the MIB Object Identifier, as shown in Figure 9: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |E| IE = mibObjectIdentifier | Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Enterprise Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = LLL | Extension 1 Type = "MIB OID" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Data Length = 0 | Extension 1 Info Length = nnn | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info = MIB Object Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 9: Extended Field Specifier Format for a non-indexed MIB Object Where: E Enterprise bit. This is the first bit of the Field Specifier. The value is always set to 0, even if the MIB Object Identifier is enterprise-specific, because the mibObjectIdentifier Information Element is an IANA standard field and is not enterprise-specific. MIB Object Identifier Information Element An IPFIX Information Element ("mibObjectIdentifier") that denotes that a MIB Object Identifier is exported in the (Options) Template Record. When the MIB Object Identifier Information Element is used, the MIB Object Identifier MUST be specified in the Extended Field Specifier for the Collecting Process to be able to decode the Records. Therefore one extension is appended to identify the MIB object which is being exported. Claise, et al. Expires August 29, 2013 [Page 16] Internet-Draft Exporting MIB Variables with IPFIX February 2013 Field Length The length of the encoded MIB data in the corresponding Data Records, in octets, not including any extension data. The definition is as [RFC5101]. Note that the Field Length can be expressed using reduced size encoding per [RFC5101]. Enterprise Number IANA enterprise number [PEN] of the authority defining the Information Element identifier in this Template Record. Extension Length The Extension Length indicates the number of extension octets. Extension 1 Type The extension type is set to "MIB OID" per the extension types in Table 1, indicating that the MIB OID follows in the Extension Info. Extension 1 Data Length Since MIB OIDs contribute no additional octets to Data Records above the already specified Field Length, this field is set to zero. Extension 1 Info Length The length of the textual representation of the MIB Object Identifier that follows. Extension 1 Info The textual representation of a MIB Object Identifier as defined in Section 4. 5.3.5. Extended Field Specifier Format for an indexed MIB Object, with a MIB OID as index The mechanism for "Extended Field Specifier Format for non-indexed MIB Object" in Section 5.3.4 can be used for exporting any MIB objects, including indexed MIB objects. However, per the nature of indexing in MIB modules, every indexed object is specified by a new MIB Object Identifier, which in turn implies that a new Template Record must be used for every indexed object. For example, the ifInOctets for the interface represented by the interface ifIndex 1 Claise, et al. Expires August 29, 2013 [Page 17] Internet-Draft Exporting MIB Variables with IPFIX February 2013 is ifInOctets.1, the ifInOctets for the interface represented by the interface ifIndex 2 is ifInOctets.2, ... This makes the export mechanism for "Extended Field Specifier Format for non-indexed MIB Object" inefficient when used for indexed MIB objects. An example is shown in Section 6.1. When an indexed MIB object is exported in IPFIX, either the meaning of the exported value of each index may be identified or the complete OID segment identifying the instance can be sent as one piece. When the meaning of each index is identified, this index (or indices) may be a MIB Object Identifier (this section), an IPFIX Information Element (Section 5.3.6), or another Information Element specified elsewhere within the Flow Record (see Section 5.3.7). A MIB Object Identifier MAY be used as an index and sent as shown in Figure 10. Note that if a MIB Object Identifier with an index is used as an index then IPFIX Structured Data [RFC6313] must be used to group the index MIB and its indices together as a single Information Element which can be used as an index as described above. An example is shown in Section 6.11. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |E| IE = mibObjectIdentifier | Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Enterprise Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = LLL | Extension 1 Type = "MIB OID" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Data Length = 0 | Extension 1 Info Length = LL1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info = MIB Object Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 2 Type = "MIB Index"| Extension 2 Data Length = DD2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 2 Info Length = LL2 | Extension 2 Info = index ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... Extension 2 Info = index MIB OID continued | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 10: Extended Field Specifier Format for an indexed MIB Object, with a MIB OID as index Where: Claise, et al. Expires August 29, 2013 [Page 18] Internet-Draft Exporting MIB Variables with IPFIX February 2013 E Enterprise bit. This is the first bit of the Field Specifier. The value is always set to 0, even if the MIB Object Identifier is enterprise-specific, because the mibObjectIdentifier Information Element is an IANA standard field and is not enterprise-specific. MIB Object Identifier Information Element An IPFIX Information Element ("mibObjectIdentifier") that denotes that a MIB Object Identifier is exported in the (Options) Template Record. When the MIB Object Identifier Information Element is used, the MIB Object Identifier MUST be specified in the Extended Field Specifier for the Collecting Process to be able to decode the Records. Therefore two extensions are appended: extension 1 indicates the MIB object which is being exported, while extension 2 identifies the indexing MIB. Field Length The length of the encoded MIB data in the corresponding Data Records, in octets, not including any extension data. The definition is as [RFC5101]. Note that the Field Length can be expressed using reduced size encoding per [RFC5101]. Enterprise Number IANA enterprise number [PEN] of the authority defining the Information Element identifier in this Template Record. Extension Length The Extension Length indicates the number of extension octets. Extension 1 Type The extension type is set to "MIB OID" per the extension types in Table 1, indicating that the MIB OID follows in the Extension Info. Extension 1 Data Length Since MIB OIDs contribute no additional octets to Data Records above the already specified Field Length, this field is set to zero. Claise, et al. Expires August 29, 2013 [Page 19] Internet-Draft Exporting MIB Variables with IPFIX February 2013 Extension 1 Info Length The length of the textual representation of the MIB Object Identifier that follows. Extension 1 Info The textual representation of a MIB Object Identifier as defined in Section 4. Extension 2 Type The extension type is set to "MIB Index" per the extension types in Table 1, indicating that the MIB OID is indexed by another MIB. Extension 2 Data Length The Extension Data Length indicates the number of additional octets which the extension (ie, the MIB index) contributes to the corresponding Data Records. This may be zero or more, and may be encoded using IPFIX variable-length encoding per section 7 of [RFC5102]. The index octets immediately follow the MIB OID value in the Data Records. Extension 2 Info Length The length of the textual representation of the index MIB Object Identifier that follows. Extension 2 Info The textual representation of the index MIB Object Identifier as defined in Section 4. If the MIB OID has multiple indices, then these are indicated in further Extensions similar to Extension 2. 5.3.6. Extended Field Specifier Format for an indexed MIB Object, with an IPFIX Information Element as index An IPFIX Information Element MAY be used as a MIB index as shown in Figure 11. Claise, et al. Expires August 29, 2013 [Page 20] Internet-Draft Exporting MIB Variables with IPFIX February 2013 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |E| IE = mibObjectIdentifier | Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Enterprise Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = LLL | Extension 1 Type = "MIB OID" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Data Length = 0 | Extension 1 Info Length = LL1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info = MIB Object Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 2 Type = "IE Index" | Extension 2 Data Length = DD2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 2 Info Length = LL2 |Extension 2 Info = index IE ...| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... Extension 2 Info = index IE continued | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 11: Extended Field Specifier Format for an indexed MIB Object, with an IPFIX Information Element as index Where: E Enterprise bit. This is the first bit of the Field Specifier. The value is always set to 0, even if the MIB Object Identifier is enterprise-specific, because the mibObjectIdentifier Information Element is an IANA standard field and is not enterprise-specific. MIB Object Identifier Information Element An IPFIX Information Element ("mibObjectIdentifier") that denotes that a MIB Object Identifier is exported in the (Options) Template Record. When the MIB Object Identifier Information Element is used, the MIB Object Identifier MUST be specified in the Extended Field Specifier for the Collecting Process to be able to decode the Records. Therefore two extensions are appended: extension 1 indicates the MIB object which is being exported, while extension 2 identifies the indexing Information Element. Claise, et al. Expires August 29, 2013 [Page 21] Internet-Draft Exporting MIB Variables with IPFIX February 2013 Field Length The length of the encoded MIB data in the corresponding Data Records, in octets, not including any extension data. The definition is as [RFC5101]. Note that the Field Length can be expressed using reduced size encoding per [RFC5101]. Enterprise Number IANA enterprise number [PEN] of the authority defining the Information Element identifier in this Template Record. Extension Length The Extension Length indicates the number of extension octets. Extension 1 Type The extension type is set to "MIB OID" per the extension types in Table 1, indicating that the MIB OID follows in the Extension Info. Extension 1 Data Length Since MIB OIDs contribute no additional octets to Data Records above the already specified Field Length, this field is set to zero. Extension 1 Info Length The length of the textual representation of the MIB Object Identifier that follows. Extension 1 Info The textual representation of the MIB Object Identifier as defined in Section 4. Extension 2 Type The extension type is set to "IE Index" per the extension types in Table 1, indicating that the MIB OID is indexed by an IPFIX Information Element. Extension 2 Data Length The Extension Data Length indicates how many octets the index value contributes to the corresponding Data Record. The index Claise, et al. Expires August 29, 2013 [Page 22] Internet-Draft Exporting MIB Variables with IPFIX February 2013 octets immediately follow the MIB OID value in the Data Record. Reduced size encoding or variable length encoding may be used. Extension 2 Info Length The length of the following Information Element information. See below. Extension 2 Info The Information Element which indexes the MIB. When the index is a standard IPFIX Information Element, the Extension Info contains the Information Element identifier with the E bit set to zero, as shown in Figure 12. In this case, the Extension Info Length is 2. 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| Information Element Ident. | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 12: Extension Info for a standard IPFIX Information Element When the index is an Enterprise Specific IPFIX Information Element, the Extension Info contains the Information Element identifier with the E bit set to one, immediately followed by the 32-bit Enterprise Number, as shown in Figure 13. In this case, the Extension Info Length is 6. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1| Information Element Ident. | Enterprise Number ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... Enterprise Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 13: Extension Info for an Enterprise Specific IPFIX Information Element If the MIB OID has multiple indices, then these are indicated in further Extensions similar to Extension 2. Claise, et al. Expires August 29, 2013 [Page 23] Internet-Draft Exporting MIB Variables with IPFIX February 2013 5.3.7. Extended Field Specifier Format for an indexed MIB Object, with a previous IPFIX Information Element as index An optimization for the Extended Field Specifier Format for an Indexed MIB object as specified in Section 5.3.5 and Section 5.3.6 is to use an IPFIX Information Element which is already present in the Flow definition as the index for indexed MIB object. This makes a clear link between the Flow Record values and the MIB variable index, and avoids repetition of the index. For example, if a Flow Record definition contains the source IP address, the destination IP address, and the ingressInterface Information Element as Flow Keys, this implies that the IP address pairs are seen on that specific interface. If the ifInOctets, indexed by that specific interface, is added to the Flow Record, it's clear from the Flow Record that the ifInOctets is related to the same interface. If the ifInOctets was indexed by the ifIndex (as specified in Section 5.3.5), the Collector would have to hardcode that the semantic of ifIndex MIB variable is equivalent to the ingressInterface Information Element. When an indexed MIB object is exported in IPFIX, the index (or indices) MAY be an IPFIX Information Element(s) previously specified in the flow record. Note that this/these IPFIX Information Element(s) MAY be enterprise-specific. Indexed MIB objects with existing IPFIX Information Elements as index, are exported as shown in Figure 14. Claise, et al. Expires August 29, 2013 [Page 24] Internet-Draft Exporting MIB Variables with IPFIX February 2013 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |E| IE = mibObjectIdentifier | Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Enterprise Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = LLL | Extension 1 Type = "MIB OID" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Data Length = 0 | Extension 1 Info Length = LL1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info = MIB Object Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type2="previousIE Index" | Extension 2 Data Length = 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 2 Info Length = LL2 | Extension 2 Info = position | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 14: Extended Field Specifier Format for an indexed MIB Object, with an existing IPFIX Information Element as index Where: E Enterprise bit. This is the first bit of the Field Specifier. The value is always set to 0, even if the MIB Object Identifier is enterprise-specific, because the mibObjectIdentifier Information Element is an IANA standard field and is not enterprise-specific. MIB Object Identifier Information Element An IPFIX Information Element ("mibObjectIdentifier") that denotes that a MIB object is exported in the (Options) Template Record. When the MIB Object Identifier Information Element (mibObjectIdentifier) is used, the MIB Object Identifier must be specified in the MIB Object Identifier Extended Field Specifier for the Collecting Process to be able to decode the Records. Field Length The length of the encoded MIB data in the corresponding Data Records, in octets, not including any extension data. The definition is as [RFC5101]. Note that the Field Length does Claise, et al. Expires August 29, 2013 [Page 25] Internet-Draft Exporting MIB Variables with IPFIX February 2013 not include the length of the index fields, since these are specified separately. Note that the Field Length can be expressed using reduced size encoding per [RFC5101]. Enterprise Number IANA enterprise number [PEN] of the authority defining the Information Element identifier in this Template Record. Extension Length The Extension Length indicates the number of extension octets. Extension 1 Type The extension type is set to "MIB OID" per the extension types in Table 1, indicating that the MIB OID follows in the Extension Info. Extension 1 Data Length Since MIB OIDs contribute no additional octets to Data Records above the already specified Field Length, this field is set to zero. Extension 1 Info Length The length of the textual representation of the MIB Object Identifier that follows. Extension 1 Info The textual representation of a MIB Object Identifier as defined in Section 4. Extension 2 Type The extension type is set to "previousIE Index" per the extension types in Table 1, indicating that the MIB OID is indexed by another Information Element within the Flow Record. Extension 2 Data Length Since the indexing Information Element is specified elsewhere in the Flow Record, the index contributes no additional octets to Data Records above the already specified Field Length. Therefore this field is set to zero. Claise, et al. Expires August 29, 2013 [Page 26] Internet-Draft Exporting MIB Variables with IPFIX February 2013 Extension 2 Info Length The length of the previousIE Index Info that follows. This could be 1 or 2. Extension 2 Info The zero-based position of the indexing Information Element within this Flow Record, as would be specified by an informationElementIndex element. This MUST be a previous Information Element (ie, one which is specified earlier in the Flow Record) so that the index value is already known. If the MIB OID has multiple indices, then these are indicated in further Extensions similar to Extension 2. 5.3.8. Extended Field Specifier Format for an Indexed MIB Object, with an IPFIX Information Element for the OID segment identifying the instance When MIB objects are to be exported, the Exporter may need to interact with the MIB instrumentation in an SNMP agent to obtain the required information. For some SNMP agents, the MIB instrumentation by design does not have knowledge of the OID of the indice(s) that identify the instance of the MIB object being accessed. For example, when accessing a MIB object ifInOctets.10, the MIB instrumentation code may not know that the object ifInOctets is indexed by ifIndex, it is sufficient for it to map the value (10) of the ifIndex to an interface on the device. For such SNMP agents, the Exporter can not use the methods described in Section 5.3.5, Section 5.3.6, and Section 5.3.7 without making extensive changes to the existing MIB instrumentation. An alternate method for exporting Indexed MIB objects in such cases is to convey only the value(s) of the indice(s) that identify the instances being exported. The index count and OIDs of the indice(s) are not conveyed in the IPFIX template record. The Collecting Process is assumed to have the intelligence to understand how the exported objects are indexed. For example, it can either compile this information from the MIB Module where this object type is defined or it may be hardcoded with this information for specific MIB objects that are of interest to it. The object identifier of the indexed MIB object is split into two parts. The first part is the OID prefix which is the OID of the corresponding object type. This is exported as a "MIB OID" in an Extended Field Specifier as shown earlier. TODO: insert xref. Claise, et al. Expires August 29, 2013 [Page 27] Internet-Draft Exporting MIB Variables with IPFIX February 2013 The second part is the OID segment identifying the instance. The "MIB Instance Identifier" extension type is defined for conveying the instance identification segment of an indexed MIB object's OID in string format. While the OID prefix is sent in the template record, the instance identifier segment is sent in the Data Record. Since the instance identifier segment of the MIB OID is in the data-record, the same template record can be used for exporting different instances of the same MIB object. Indexed MIB objects with a MIB Instance Identifier as index are exported as shown in Figure 15: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |E| IE = mibObjectIdentifier | Field Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Enterprise Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = LLL | Extension 1 Type = "MIB OID" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Data Length = 0 | Extension 1 Info Length = LL1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info = MIB Object Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type="MIB Instance Identifier"| Extension 2 Data Length = DD2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 2 Info Length = LL2 | Extension 2 Info = index ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... Extension 2 Info = index MIB OID continued | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 15: Extended Field Specifier Format for an indexed MIB Object using MIB Instance Identifier as Index Where: E Enterprise bit. This is the first bit of the Field Specifier. The value is always set to 0, even if the MIB Object Identifier is enterprise-specific, because the mibObjectIdentifier Information Element is an IANA standard field and is not enterprise-specific. Claise, et al. Expires August 29, 2013 [Page 28] Internet-Draft Exporting MIB Variables with IPFIX February 2013 MIB Object Identifier Information Element An IPFIX Information Element ("mibObjectIdentifier") that denotes that a MIB Object Identifier is exported in the (Options) Template Record. When the MIB Object Identifier Information Element is used, the MIB Object Identifier MUST be specified in the Extended Field Specifier for the Collecting Process to be able to decode the Records. Therefore two extensions are appended: extension 1 indicates the MIB object which is being exported, while extension 2 identifies the indexing MIB instance. Field Length The length of the encoded MIB data in the corresponding Data Records, in octets, not including any extension data. The definition is as [RFC5101]. Note that the Field Length can be expressed using reduced size encoding per [RFC5101]. Enterprise Number IANA enterprise number [PEN] of the authority defining the Information Element identifier in this Template Record. Extension Length The Extension Length indicates the number of extension octets. Extension 1 Type The extension type is set to "MIB OID" per the extension types in Table 1, indicating that the MIB OID follows in the Extension Info. Extension 1 Data Length Since MIB OIDs contribute no additional octets to Data Records above the already specified Field Length, this field is set to zero. Extension 1 Info Length The length of the textual representation of the MIB Object Identifier that follows. Claise, et al. Expires August 29, 2013 [Page 29] Internet-Draft Exporting MIB Variables with IPFIX February 2013 Extension 1 Info The textual representation of a MIB Object Identifier as defined in Section 4. Extension 2 Type The extension type is set to "MIB Instance Identifier" per the extension types in Table 1, indicating that the MIB OID is indexed by a MIB Instance. Extension 2 Data Length The Extension Data Length indicates how many octets the MIB Instance Identifier contributes to the corresponding Data Record. The index octets immediately follow the MIB OID value in the Data Record. Reduced size encoding or variable length encoding may be used. Extension 2 Info Length Since the MIB Instance Identifier is sent in Data Records, this extension contains no additional Info. Therefore the Info Length is zero. Extension 2 Info Since the MIB Instance Identifier is sent in Data Records, this extension contains no additional Info. 5.4. Identifying the SNMP Context Each MIB OID is looked up in a specific context, usually the default context. If exporting a MIB OID value that isn't in the default context then the context string MUST be identified and associated with the MIB OID. This can be done on a per template basis by exporting an Options Template Record. A new IPFIX Information Element, "mibContextIdentifier" has been allocated for this purpose. See Section 11. 5.5. Template Management Templates are managed as per [RFC5101]. The Set ID field MUST contain the value TBD1 for any Template Set that contains an Extended Field Specifier. The Template Withdrawal Message for such a Template must also use a Set ID field containing Claise, et al. Expires August 29, 2013 [Page 30] Internet-Draft Exporting MIB Variables with IPFIX February 2013 the value TBD1. The Set ID field MUST contain the value TBD2 for any Option Template Set that contains an Extended Field Specifier. The Template Withdrawal Message for such an Option Template must also use a Set ID field containing the value TBD2. 6. Example Use Cases 6.1. Without Using the Specifications in this Document This example shows the need for indexed MIB objects using the example of exporting ifInOctets from Section 5.3.5. Note that ifInOctets.1 has the MIB Object Identifier 1.3.6.1.2.1.2.2.1.10.1 A Template Record for exporting the ifInOctets for the interface represented by the interface ifIndex 1 (i.e., ifInOctets.1) is shown in Figure 16. While this may be useful for exporting the single ifInOctets.1 field, clearly additional Templates are required in order to export ifInOctets.2, ifInOctets.3, etc. Therefore Indexed MIB objects (per Section 5.3.5) are required in order to export arbitrary ifInOctets.x. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = TBD1 | Length = 40 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 256 | Field Count = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = mibObjectIdentifier | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = 26 | Extension 1 Type = "MIB OID" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Data Length = 0 | Extension 1 Info Length = 22 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info = MIB Object Identifier ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier = "1.3.6.1.2.1.2.2.1.10.1" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Claise, et al. Expires August 29, 2013 [Page 31] Internet-Draft Exporting MIB Variables with IPFIX February 2013 Figure 16: Template for exporting ifInOctets.1 6.2. Non-indexed MIB Object: Established TCP Connections The number of established TCP connections of a remote network device could be monitored by configuring it to periodically export the number of established TCP connections to a centralized Collector. In this example, the Exporter would export an IPFIX Message every 30 minutes that contained Data Records detailing the number of established TCP connections. The table of data that is to be exported looks like: +-------------------------+-----------------------+ | TIMESTAMP | ESTABLISHED TCP CONN. | +-------------------------+-----------------------+ | StartTime + 0 seconds | 10 | | StartTime + 60 seconds | 14 | | StartTime + 120 seconds | 19 | | StartTime + 180 seconds | 16 | | StartTime + 240 seconds | 23 | | StartTime + 300 seconds | 29 | +-------------------------+-----------------------+ Table 2: Established TCP Connections The Template Record for such a Data Record will detail two Information Elements: 1. flowStartSeconds from [RFC5102], Information Element 150: The absolute timestamp of the first packet of this Flow. 2. tcpCurrEstab from [RFC4022], Object ID "1.3.6.1.2.1.6.9": The number of TCP connections for which the current state is either ESTABLISHED or CLOSE-WAIT. Figure 17 shows the exported Template Set detailing the Template Record for exporting the number of established TCP connections (see Section 6.2). Claise, et al. Expires August 29, 2013 [Page 32] Internet-Draft Exporting MIB Variables with IPFIX February 2013 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = TBD1 | Length = 37 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 257 | Field Count = 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = flowStartSeconds | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = mibObjectIdentifier | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = 19 | Extension 1 Type = "MIB OID" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Data Length = 0 | Extension 1 Info Length = 15 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info = MIB Object Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier = "1.3.6.1.2.1.6.9" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+ Figure 17: Example of tcpCurrEstab Template Set Figure 18 shows the start of the Data Set for exporting the number of established TCP connections (see Section 6.2). Claise, et al. Expires August 29, 2013 [Page 33] Internet-Draft Exporting MIB Variables with IPFIX February 2013 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = 257 | Length = 52 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | StartTime + 0 seconds | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 10 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | StartTime + 60 seconds | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 14 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | StartTime + 120 seconds | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 19 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | StartTime + 180 seconds | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 16 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | StartTime + 240 seconds | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 23 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | StartTime + 300 seconds | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 29 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 18: Example of tcpCurrEstab Data Set 6.3. Enterprise Specific MIB Object: Detailing CPU Load History For the sake of demonstrating a enterprise-specific MIB object, a non-indexed MIB object is chosen for simplicity. The CPU Usage of a remote network device could be monitored by configuring it to periodically export CPU usage information, i.e. the cpmCPUTotal1minRev from the proprietary CISCO-PROCESS-MIB, Object ID "1.3.6.1.4.1.9.9.109.1.1.1.1.7", to a centralized Collector. In this example, the Exporter would export an IPFIX Message every 30 minutes that contained Data Records detailing the CPU 1 minute busy average at 1 minute intervals. The table of data that is to be exported looks like: Claise, et al. Expires August 29, 2013 [Page 34] Internet-Draft Exporting MIB Variables with IPFIX February 2013 +-------------------------+---------------------+ | TIMESTAMP | CPU BUSY PERCENTAGE | +-------------------------+---------------------+ | StartTime + 0 seconds | 10% | | StartTime + 60 seconds | 14% | | StartTime + 120 seconds | 19% | | StartTime + 180 seconds | 16% | | StartTime + 240 seconds | 23% | | StartTime + 300 seconds | 29% | +-------------------------+---------------------+ Table 3: CPU Usage Data The Template Record for such a Data Record will detail two Information Elements: 1. flowStartSeconds from [RFC5102], Information Element 150: The absolute timestamp of the first packet of this Flow. 2. cpmCPUTotal1minRev, the overall CPU busy percentage in the last one-minute period Figure 19 shows the exported Template Set detailing the Template Record for exporting CPU Load (see Section 6.3). Claise, et al. Expires August 29, 2013 [Page 35] Internet-Draft Exporting MIB Variables with IPFIX February 2013 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = TBD1 | Length = 53 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 258 | Field Count = 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = flowStartSeconds | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = mibObjectIdentifier | Field Length = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = 33 | Extension 1 Type = "MIB OID" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Data Length = 0 | Extension 1 Info Length = 29 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info = MIB Object Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier = "1.3.6.1.4.1.9.9.109.1.1.1.1.7" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB OID | +-+-+-+-+-+-+-+-+ Figure 19: Example of CPU Load Template Set Note that although cpmCPUTotal1minRev is 32 bits long, reduced size encoding ([RFC5101]) has been used to encoded it within a single octet. This example stresses that, even though the OID cpmCPUTotal1minRev is enterprise-specific, the E bit for the mibObjectIdentifier is set to "0" since the "mibObjectIdentifier" Information Element is not enterprise-specific. The corresponding Data Set does not add any value for this example, and is therefore not displayed. Claise, et al. Expires August 29, 2013 [Page 36] Internet-Draft Exporting MIB Variables with IPFIX February 2013 6.4. Indexed MIB Object with Two OIDs: The ipIfStatsInForwDatagrams MIB objects may be indexed by multiple indices. Note that all the indices apply to the MIB object, i.e. index 2 is not an index of index 1. (If that was the case, then IPFIX Structured Data [RFC6313] must be used to group the indices.) This example shows the export of ipIfStatsInForwDatagrams from the IP-MIB [RFC4293] indexed by the ipIfStatsIPVersion and ipIfStatsIfIndex which are provided as scope fields in an IPFIX option. Note that since these fields are used as indices for ipIfStatsInForwDatagrams, they don't need their own indices to be identified. The Options Template Record for the example Data Record contains the following Information Elements: 1. ipIfStatsIPVersion (1.3.6.1.2.1.4.31.3.1.1) (scope field) 2. ipIfStatsIfIndex (1.3.6.1.2.1.4.31.3.1.2) (scope field) 3. ipIfStatsInForwDatagrams (1.3.6.1.2.1.4.31.3.1.12) (non-scope field) indexed by ipIfStatsIPVersion and ipIfStatsIfIndex Note that due to the "previousIE Index" indexing, the ipIfStatsIPVersion and ipIfStatsIfIndex values do not have to be repeated in the Data Records. Figure 20 shows the exported Options Template Set. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = TBD2 | Length = 127 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 259 | Field Count = 3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope Field Count = 2 |0| scope1=mibObjectIdentifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope Field 1 Length = 1 | Extension Length = 28 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Type = "MIB OID" | Extension Data Length = 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Info Length = 22 | Extension Info = MIB OID ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MIB Object Identifier = "1.3.6.1.2.1.4.31.3.1.1" ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | Claise, et al. Expires August 29, 2013 [Page 37] Internet-Draft Exporting MIB Variables with IPFIX February 2013 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| scope2=mibObjectIdentifier | Scope Field 2 Length = 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = 28 | Extension Type = "MIB OID" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Data Length = 0 | Extension Info Length = 22 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MIB Object Identifier = "1.3.6.1.2.1.4.31.3.1.2" ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |MIB Object Identifier continued|0| field = mibObjectIdentifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Length = 4 | Extension Length = 43 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Type = "MIB OID" | Extension 1 Data Length = 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info Length = 23 | Extension 1 Info = MIB OID ...| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MIB Object Identifier = "1.3.6.1.2.1.4.31.3.1.12" ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB OID |Ext 2 Type = "previousIE Index"|Ext2 DataLen...| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Ext2 Data Len=0| Extension 2 Info Length = 1 | Ext2 Info = 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Ext 3 Type = "previousIE Index"| Extension 3 Data Length = 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 3 Info Length = 1 | Ext3 Info = 1 | Claise, et al. Expires August 29, 2013 [Page 38] Internet-Draft Exporting MIB Variables with IPFIX February 2013 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 20: Example of an Options Template for an Indexed MIB Object with two indices. 6.5. Indexed MIB Object with an IPFIX Information Element: Output Interface Queue Size in PSAMP Packet Report If a PSAMP Packet Report [RFC5476] was generated on any dropped packets on an interface then it may be desirable to know if the send queue on the output interface was full. This could be done be exporting the size of the send queue (ifOutQLen) in the same Data Record as the PSAMP Packet Report. The exported data looks like: +-----------+-----------+--------+------------+---------------------+ | SRC ADDR | DST ADDR | PAK | OUTPUT I/F | OUTPUT Q. LEN | | | | LEN | | (ifOutQLen) | +-----------+-----------+--------+------------+---------------------+ | 192.0.2.1 | 192.0.2.3 | 150 | Eth 1/0 | 45 | | | | | (15) | | | 192.0.2.4 | 192.0.2.9 | 350 | Eth 1/0 | 45 | | | | | (15) | | | 192.0.2.3 | 192.0.2.9 | 650 | Eth 1/0 | 23 | | | | | (15) | | | 192.0.2.4 | 192.0.2.6 | 350 | Eth 1/1 | 0 | | | | | (16) | | +-----------+-----------+--------+------------+---------------------+ Table 4: Packet Report with Interface Output Queue Length (ifOutQLen) Data The MIB object for the Interface Output Queue Length, ifOutQLen ("1.3.6.1.2.1.2.2.1.21"), is indexed by the ifIndex interface index as detailed in the IF-MIB [RFC2863]. If, for example, the interface index of "Eth 1/0" in the example is 15, the full MIB Object Identifier for (ifOutQLen) would be "1.3.6.1.2.1.2.2.1.21.15". Without a method to specify the index the full MIB OID would have to be used, which would mean specifying a new Template Record. Rather than export a separate Template Record for each Interface Index, it is more practical to identify the index in the Data Record itself. In fact, only how the indexed object was indexed is necessary, although it is often useful to specify the index value. The example identifies the Egress Interface, but for other uses it may be sufficient to know that the ifOutQLen value was taken for the interface that the packet was switched out of, without identifying Claise, et al. Expires August 29, 2013 [Page 39] Internet-Draft Exporting MIB Variables with IPFIX February 2013 the actual interface. The Template Record for the example Data Record contains the following Information Elements: 1. sourceIPv4Address 2. destinationIPv4Address 3. totalLengthIPv4 4. egressInterface 5. ifOutQLen indexed by: egressInterface Figure 21 shows the exported Template Set detailing the Template for exporting a PSAMP Report with Interface Output Queue Length (ifOutQLen). Claise, et al. Expires August 29, 2013 [Page 40] Internet-Draft Exporting MIB Variables with IPFIX February 2013 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = TBD1 | Length = 63 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 260 | Field Count = 5 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = sourceIPv4Address | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = destinationIPv4Address | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = totalLengthIPv4 | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = egressInterface | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = mibObjectIdentifier | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = 35 | Extension 1 Type = "MIB OID" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Data Length = 0 | Extension 1 Info Length = 20 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info = MIB Object Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier = "1.3.6.1.2.1.2.2.1.21" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Ext2 Type = "previousIE index"| Extension 2 Data Length = 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 2 Info Length = 1 | Ext 2 Info = 3| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 21: Example of Template for a PSAMP Report with ifOutQLen indexed by egressInterface The corresponding IPFIX Data Record is shown in Figure 22. For the sake of the example, the interface index of "Eth 1/0" is 15 and the interface index of "Eth 1/1" is 16. Claise, et al. Expires August 29, 2013 [Page 41] Internet-Draft Exporting MIB Variables with IPFIX February 2013 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = 260 | Length = 84 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.0.2.1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.0.2.3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 150 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 15 (Eth 1/0) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 45 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.0.2.4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.0.2.9 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 350 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 15 (Eth 1/0) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 45 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.0.2.3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.0.2.9 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 650 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 15 (Eth 1/0) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 23 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.0.2.4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.0.2.6 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 350 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 16 (Eth 1/1) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 22: Example of PSAMP Packet Report with ifOutQLen indexed by egressInterface Claise, et al. Expires August 29, 2013 [Page 42] Internet-Draft Exporting MIB Variables with IPFIX February 2013 6.6. Indexed MIB Object with an OID: Output Interface Queue Size in PSAMP Packet Report Following on the example from the previous section (see Section 6.5), if the Template Record for the example Data Record does not contain the egressInterface, the ifOutQLen must be indexed by the ifIndex interface index as detailed in the IF-MIB [RFC2863]: The Template Record for the example Data Record contains the following Information Elements: 1. sourceIPv4Address 2. destinationIPv4Address 3. totalLengthIPv4 4. ifOutQLen indexed by: ifIndex Figure 23 shows the exported Template Set detailing the Template for exporting a PSAMP Report with Interface Output Queue Length (ifOutQLen) but using the ifIndex MIB object as the exported index. Claise, et al. Expires August 29, 2013 [Page 43] Internet-Draft Exporting MIB Variables with IPFIX February 2013 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = TBD1 | Length = 70 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 261 | Field Count = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = sourceIPv4Address | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = destinationIPv4Address | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = totalLengthIPv4 | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = mibObjectIdentifier | Field Length = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = 26 | Extension 1 Type = "MIB OID" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Data Length = 0 | Extension 1 Info Length = 20 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info = MIB Object Identifier ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier = "1.3.6.1.2.1.2.2.1.21" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 2 Type = "MIB index"| Extension 2 Data Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 2 Info Length = 19 | Extension 2 Info = MIB OID ...| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MIB Object Identifier = "1.3.6.1.2.1.2.2.1.1" ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB OID | +-+-+-+-+-+-+-+-+ Figure 23: Example of a Template for a PSAMP Report with ifOutQLen using ifIndex from IF-MIB [RFC2863] as an index Note that IPFIX reduced size encoding [RFC5101] has been used in this Claise, et al. Expires August 29, 2013 [Page 44] Internet-Draft Exporting MIB Variables with IPFIX February 2013 example to express ifOutQLen in a single octet, rather than the 32 bits specified in the IF-MIB [RFC2863]. The corresponding IPFIX Data Record is shown in Figure 24. For the sake of the example, the interface index of "Eth 1/0" is 15 and the interface index of "Eth 1/1" is 16. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = 261 | Length = 72 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.0.2.1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 192.0.2.3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 150 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 45 | 15 ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | 192.0.2.4 ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | 192.0.2.9 ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | 350 ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | 45 | 15 ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | 192.0.2.3 ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | 192.0.2.9 ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | 650 ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | 23 | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... 15 | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... 192.0.2.4 | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... 192.0.2.6 | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... 350 | 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 16 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 24: Example of PSAMP Packet Report with the ifOutQLen using Claise, et al. Expires August 29, 2013 [Page 45] Internet-Draft Exporting MIB Variables with IPFIX February 2013 ifIndex from IF-MIB [RFC2863] as an index 6.7. Indexed MIB Objects with a mix of MIB OID and IPFIX Information Element TODO. 6.8. Indexed MIB Object with MIBInstanceIdentifier Information Element: ipIfStatsOutOctets This example shows the export of ipIfStatsOutOctets from the IP-MIB [RFC4293] indexed by the ipIfStatsIPVersion and ipIfStatsIfIndex, using the MIBInstanceIdentifier Information Element to carry the index information. The exported data looks like: +--------------------+------------------+--------------------+ | ipIfStatsIPVersion | ipIfStatsIfIndex | ipIfStatsOutOctets | +--------------------+------------------+--------------------+ | 1(IPv4) | 10 | 235876 | | 2(IPv6) | 11 | 38688 | +--------------------+------------------+--------------------+ Table 5: The number octets in IP datagrams delivered to the lower layers for transmission The MIB object ipIfStatsOutOctets ("1.3.6.1.2.1.4.31.3.1.32"), is indexed by ipIfStatsIPVersion and ipIfStatsIfIndex as detailed in IP- MIB [RFC4293]. The instance of the ipIfStatsOutOctets for the IPv4 protocol on the interface identified by ifIndex 10 is identified in the Data Record with the instance identifier segment ("1.10") in string format, while the instance of the ipIfStatsOutOctets for the IPv6 protocol on the interface identified by ifIndex 11 is identified in the Data Record with the instance identifier segment ("2.11") in string format. The Template Record for the example Data Records contains the following Information Elements: 1. ipIfStatsOutOctets (1.3.6.1.2.1.4.31.3.1.32) Figure 25 shows the exported Template Set. Claise, et al. Expires August 29, 2013 [Page 46] Internet-Draft Exporting MIB Variables with IPFIX February 2013 0 1 2 2 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = TBD1 | Length = 49 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 262 | Field Count = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| IE = mibObjectIdentifier | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = 35 | Extension 1 Type = "MIB OID" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Data Length = 0 | Extension 1 Info Length = 23 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info = MIB Object Identifier ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ...MIB Object Identifier = "1.3.6.1.2.1.4.31.3.1.32" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued | Ext2 Type=... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | =MIBinstanceID| Ext 2 Data Length = 0xFFFF |Ext2 InfoLen...| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Ext2InfoLen=0 | +-+-+-+-+-+-+-+-+ Figure 25: Example of a Template for MIB Objects that use the MIBInstanceIdentifier Information Element The corresponding IPFIX Data Record is shown in Figure 26. Variable length encoding is used for MIBInstanceIdentifier Information Element. Claise, et al. Expires August 29, 2013 [Page 47] Internet-Draft Exporting MIB Variables with IPFIX February 2013 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = 262 | Length = 22 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ipIfStatsOutOctets = 235876 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Length = 4 | "1.10"... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | ipIfStatsOutOctets = 38688 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | Length = 4 | "2.11"... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 26: Example of ipIfStatsOutOctets using ipIfStatsIPVersion and ipIfStatsIfIndex as indices 6.9. Using MIB Objects as IPFIX Options Scope fields Both indexed and non-indexed MIB Objects may be used as IPFIX Options Scope fields as discussed in Section 5.2. 6.9.1. Using non-Indexed MIB Objects as Option Scope fields In this example, a Cisco Telepresence system uses an IPFIX option to report bandwidth usage statistics. The ctpcLocalAddrType and ctpcLocalAddr OIDs from the CISCO-TELEPRESENCE-CALL MIB are used as scope fields to identify the Telepresence system. The ctpcLocalAddrType is expressed with a fixed size of 1 octet, while the ctpcLocalAddr is expressed using a variable length field. These scope fields are followed by two non-scope fields containing the number of packets and bytes. IPFIX reduced size encoding is used to express each of these fields in 32 bits. Therefore the Options Template Record for the example Data Record contains the following Information Elements: 1. ctpcLocalAddrType (1.3.6.1.4.1.9.9.644.1.2.1) (scope field) 2. ctpcLocalAddr (1.3.6.1.4.1.9.9.644.1.2.2) (scope field) 3. octetDeltaCount (non-scope field) 4. packetDeltaCount (non-scope field) Claise, et al. Expires August 29, 2013 [Page 48] Internet-Draft Exporting MIB Variables with IPFIX February 2013 The IPFIX Options Template Record is shown in Figure 27. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = TBD2 | Length = 89 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 263 | Field Count = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope Field Count = 2 |0| scope1=mibObjectIdentifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope Field 1 Length = 1 | Extension Length = 28 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Type = "MIB OID" | Extension Data Length = 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Info Length = 22 | Extension Info = MIB OID ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MIB Object Identifier = "1.3.6.1.4.1.9.9.644.1.2.1" ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| scope2=mibObjectIdentifier | Scope Field 2 Length = 0xFFFF | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Length = 31 | Extension Type = "MIB OID" | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Data Length = 0 | Extension Info Length = 25 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Info = MIB Object Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier = "1.3.6.1.4.1.9.9.644.1.2.2" ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB OID |0| octetDeltaCount = 1 |Field Length...| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Field Length =4|0| packetDeltaCount = 2 |Field Length...| Claise, et al. Expires August 29, 2013 [Page 49] Internet-Draft Exporting MIB Variables with IPFIX February 2013 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Field Length =4| +-+-+-+-+-+-+-+-+ Figure 27: Example of an IPFIX Options Template Record using non- Indexed MIB Objects as scope fields The corresponding IPFIX Options Data Record is shown in Figure 28. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = 263 | Length = 18 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | AddrType = 1 | Length = 4 | ctpcLocalAddrsystemID = ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... 192.0.2.1 | octetDeltaCount = nnnn ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... octetDeltaCount continued | packetDeltaCount = nnnn ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... packetDeltaCount continued| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 28: Example of an IPFIX Options Data Record using non-Indexed MIB Objects as scope fields 6.9.2. Using Indexed MIB Objects as Option Scope fields In this example, interface statistics are reported using ifName and ifInOctets from the IF-MIB [RFC2863]. Both of these fields are indexed by the ifIndex. The ifName and ifIndex are scope fields. Therefore the Options Template Record for the example Data Record contains the following Information Elements: 1. ifIndex (1.3.6.1.2.1.2.2.1.1) (scope field) 2. ifName (1.3.6.1.2.1.31.1.1.1.1) (scope field) indexed by ifIndex 3. ifInOctets (1.3.6.1.2.1.2.2.1.10) (non-scope field) indexed by ifIndex The IPFIX Options Template Record is shown in Figure 29. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = TBD2 | Length = 137 | Claise, et al. Expires August 29, 2013 [Page 50] Internet-Draft Exporting MIB Variables with IPFIX February 2013 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 264 | Field Count = 3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope Field Count = 2 |0| scope1=mibObjectIdentifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope Field 1 Length = 4 | Extension Length = 25 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Type = "MIB OID" | Extension Data Length = 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension Info Length = 19 | Extension Info = MIB OID ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier = "1.3.6.1.2.1.2.2.1.1" ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB OID |0| scope2=mibObjectIdentifier | Scope2 Len... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |...Len = 0xFFFF| Extension Length = 35 | Ext1Type = ...| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Ext1="MIB OID"| Extension 1 Data Length = 0 | Ext1InfoLen...| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Ext1InfoLen=22| Extension 1 Info = MIB Object Identifier ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier = "1.3.6.1.2.1.31.1.1.1.1" ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued | Ext2Type = ...| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Ex2="prevIEidx"| Extension 2 Data Length = 0 | Ext2InfoLen...| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Ext2InfoLen=1 | Ext2Info = 0 |0| Field1=mibObjectIdentifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field 1 Length = 4 | Extension Length = 33 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Type = "MIB OID" | Extension 1 Data Length = 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info Length = 20 | Extension 1 Info = MIB OID ...| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 1 Info = MIB Object Identifier ... | Claise, et al. Expires August 29, 2013 [Page 51] Internet-Draft Exporting MIB Variables with IPFIX February 2013 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier="1.3.6.1.2.1.2.2.1.10"... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier continued ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... MIB Object Identifier cont| Extension 2 Type = "prevIEidx"| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Extension 2 Data Length = 0 | Extension 2 Info Length = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Ext2Info = 0 | +-+-+-+-+-+-+-+-+ Figure 29: Example of an IPFIX Options Template Record using Indexed MIB Objects as scope fields The corresponding IPFIX Options Data Record is shown in Figure 30. For the sake of the example, the interface index of "Eth 1/1" is 15 and the ifInOctets are 1000. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = 264 | Length = 20 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ifIndex = 15 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Length = 7 | ifName = "Eth 1/1" ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... ifName continued | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ifInOctets = 1000 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 30: Example of an IPFIX Options Data Record using Indexed MIB Objects as scope fields 6.10. Using MIB Objects with IPFIX Structured Data It's possible to export both indexed and non-indexed MIB objects using IPFIX Structured Data per [RFC6313] as shown in the example below. TODO: insert example. Claise, et al. Expires August 29, 2013 [Page 52] Internet-Draft Exporting MIB Variables with IPFIX February 2013 6.11. Using IPFIX Structured Data to group the index MIB and indices TODO: insert example. 7. Configuration Considerations When configuring a MIB OID for export, consideration should be given to whether the SNMP Context String should also be configurable. If a non-default Context String is used then it should be associated with the fields as per Section 5.4. 8. The Collecting Process's Side This section describes the Collecting Process when using SCTP and PR- SCTP as the transport protocol. Any necessary changes to the Collecting Process specifically related to TCP or UDP transport protocols are specified in section 10 of [RFC5101]. The specifications in section 9 of [RFC5101] also apply to Collector's that implement this specification. In addition, the following specifications should be noted. A Collecting Process that implements this specification MUST be able to receive Set IDs TBD1 and TBD2, as specified in this document. A Collecting Process that implements this specification MUST have access to MIB modules in order to look up the received MIB Object Identifiers and find the type and name of MIB OID fields used in received templates. It should be noted that since reduced size encoding MAY be used by the Exporting Process then the Collecting Process cannot assume a received size for a field is the maximum size it should expect for that field. If a Collecting Process receives a MIB Object Identifier that it cannot decode, it SHOULD log an error. If a Collecting Process receives a MIB Object Identifier for an indexed MIB object but isn't sent the appropriate number of indices then it SHOULD log an error, but it MAY use the Template Record to decode the Data Records as the associated indices are purely semantic information. 9. Applicability Making available the many and varied items from MIB modules opens up Claise, et al. Expires August 29, 2013 [Page 53] Internet-Draft Exporting MIB Variables with IPFIX February 2013 a wide range of possible applications for the IPFIX protocol, some quite different from the usual flow information. Some potential enhancements for traditional applications are detailed below: Some monitoring applications periodically export an interface id to interface name mapping using IPFIX Options Templates. This could be expanded to include the MIB object "ifInUcastPkts" of the IF-MIB [RFC2863] indexed using the ingressInterface Information Element, as a index. This would give the input statistics for each interface which can be compared to the flow information to ensure the sampling rate is expected. Or, if there is no sampling, to ensure that all the expected packets are being monitored. 10. Security Considerations For this extension to the IPFIX protocol, the same security considerations as for the IPFIX protocol apply [RFC5101]. The access to MIB objects is controlled by the configuration of the IPFIX exporter. This is consistent with the way IPFIX controls access to other Information Elements in general. The configuration of an IPFIX exporter determines which MIB objects are included in IPFIX flow records sent to certain collectors. Network operators should take care that only MIB objects are included in IPFIX flow records that the receiving flow collector is allowed to receive. 11. IANA Considerations 11.1. New Set IDs IPFIX Messages use two fields with assigned values. These are the IPFIX Version Number, indicating which version of the IPFIX Protocol was used to export an IPFIX Message, and the IPFIX Set ID, indicating the type of each set of information within an IPFIX Message. The previously reserved Set ID values of TBD1 and TBD2 are allocated in IANA's IPFIX Set IDs registry [IANA-SETS], and are used as specified in this document. 11.2. New Data Types A new mibObject data type must be allocated in IANA's IPFIX Information Element Data Types registry, [IANA-DATATYPES]. A new mibContext data type must be allocated in IANA's IPFIX Information Element Data Types registry, [IANA-DATATYPES]. Claise, et al. Expires August 29, 2013 [Page 54] Internet-Draft Exporting MIB Variables with IPFIX February 2013 11.3. New Information Elements A new Information Element "mibObjectIdentifier" must be allocated in IANA's IPFIX registry, [IANA-IPFIX], with the following definition: MIB Object Identifier Description: An IPFIX Information Element ("mibObjectIdentifier") that denotes that a MIB Object Identifier is exported in the (Options) Template Record. Abstract Data Type: mibObject Data Type Semantics: identifier ElementId: TBD3 Status: current Reference: [this document]. A new Information Element "mibContextIdentifier" must be allocated in IANA's IPFIX registry, [IANA-IPFIX], with the following definition: MIB Context Identifier Description: An IPFIX Information Element ("mibObjectIdentifier") that denotes that a MIB Context Identifier is exported in the (Options) Template Record. Abstract Data Type: mibContext Data Type Semantics: identifier ElementId: TBD4 Status: current Reference: [this document]. 11.4. New Extension Types registry A new registry must be defined from the extension types in Table 1. New extension types may be added to the registry subject to Expert Review [RFC5226] by the assigned IPFIX Experts. Claise, et al. Expires August 29, 2013 [Page 55] Internet-Draft Exporting MIB Variables with IPFIX February 2013 12. Acknowledgements The authors would like to thank Andrew Johnson for his collaboration on the first version of the draft. 13. References 13.1. Normative References [IANA-DATATYPES] IANA, "IPFIX Information Element Data Types registry", , . [IANA-IPFIX] IANA, "IPFIX Information Elements registry", . [IANA-SETS] IANA, "IPFIX Set IDs registry", . [PEN] IANA, "Private Enterprise Numbers registry", . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2578] McCloghrie, K., Ed., Perkins, D., Ed., and J. Schoenwaelder, Ed., "Structure of Management Information Version 2 (SMIv2)", STD 58, RFC 2578, April 1999. [RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group MIB", RFC 2863, June 2000. [RFC4293] Routhier, S., "Management Information Base for the Internet Protocol (IP)", RFC 4293, April 2006. [RFC5101] Claise, B., "Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information", RFC 5101, January 2008. [RFC5102] Quittek, J., Bryant, S., Claise, B., Aitken, P., and J. Meyer, "Information Model for IP Flow Information Export", RFC 5102, January 2008. [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an Claise, et al. Expires August 29, 2013 [Page 56] Internet-Draft Exporting MIB Variables with IPFIX February 2013 IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. 13.2. Informative References [RFC2982] Kavasseri, R., "Distributed Management Expression MIB", RFC 2982, October 2000. [RFC3444] Pras, A. and J. Schoenwaelder, "On the Difference between Information Models and Data Models", RFC 3444, January 2003. [RFC4022] Raghunarayan, R., "Management Information Base for the Transmission Control Protocol (TCP)", RFC 4022, March 2005. [RFC5476] Claise, B., Johnson, A., and J. Quittek, "Packet Sampling (PSAMP) Protocol Specifications", RFC 5476, March 2009. [RFC6313] Claise, B., Dhandapani, G., Aitken, P., and S. Yates, "Export of Structured Data in IP Flow Information Export (IPFIX)", RFC 6313, July 2011. Authors' Addresses Benoit Claise Cisco Systems, Inc. De Kleetlaan 6a b1 Diegem, 1813 Belgium Phone: +32 2 704 5622 Email: bclaise@cisco.com Paul Aitken Cisco Systems, Inc. 96 Commercial Quay Commercial Street Edinburgh, EH6 6LX UK Phone: +44 131 561 3616 Email: paitken@cisco.com Claise, et al. Expires August 29, 2013 [Page 57] Internet-Draft Exporting MIB Variables with IPFIX February 2013 Srikar Cisco Systems, Inc. Mail Stop BGL13/3/, SEZ Unit, Cessna Business Park, Kadubeesanahalli Village Varthur Hobli, Sarjapur Marathalli Outer Ring Road Bangalore, KARNATAKA 560 103 IN Phone: +91 80 4426 3264 Email: srikar@cisco.com Juergen Schoenwaelder Jacobs University Bremen Campus Ring 1 Bremen, 28725 Germany Phone: +49 421 200-3587 Email: j.schoenwaelder@jacobs-university.de Claise, et al. Expires August 29, 2013 [Page 58]