Movatterモバイル変換


[0]ホーム

URL:


[RFC Home] [TEXT|PDF|HTML] [Tracker] [IPR] [Info page]

PROPOSED STANDARD
Network Working Group                                 H. Hazewinkel, Ed.Request for Comments: 3747                                         I.NetCategory: Standards Track                                D. Partain, Ed.                                                                Ericsson                                                              April 2004The Differentiated Services Configuration MIBStatus of this Memo   This document specifies an Internet standards track protocol for the   Internet community, and requests discussion and suggestions for   improvements.  Please refer to the current edition of the "Internet   Official Protocol Standards" (STD 1) for the standardization state   and status of this protocol.  Distribution of this memo is unlimited.Copyright Notice   Copyright (C) The Internet Society (2004).  All Rights Reserved.Abstract   This memo describes a MIB module that provides a conceptual layer   between high-level "network-wide" policy definitions that effect   configuration of the Differentiated Services (diffserv) subsystem and   the instance-specific information that would include such details as   the parameters for all the queues associated with each interface in a   system.  This essentially provides an interface for configuring   differentiated services at a conceptually higher layer than that of   the Differentiated Services MIB.Hazewinkel & Partain        Standards Track                     [Page 1]

RFC 3747       Differentiated Services Configuration MIB      April 2004Table of Contents1.  The Internet-Standard Management Framework . . . . . . . . . .22.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .23.  Other Documents. . . . . . . . . . . . . . . . . . . . . . . .34.  Relationship to other MIBs . . . . . . . . . . . . . . . . . .34.1.  The Policy-based Management MIB Module . . . . . . . . .34.2.  The Differentiated Services MIB Module . . . . . . . . .45.  The Differentiated Services Configuration MIB Module Design. .56.  Template Cloning . . . . . . . . . . . . . . . . . . . . . . .66.1.  An Approach to Template Cloning. . . . . . . . . . . . .66.2.  Example. . . . . . . . . . . . . . . . . . . . . . . . .76.2.1.  The Initial Situation. . . . . . . . . . . . . .86.2.2.  The Configuration Template . . . . . . . . . . .96.2.3.  Applying the Template. . . . . . . . . . . . . .116.2.4.  Applying the Template Using SNMP Messages. . . .147.  Managed Objects Definitions (MIB Module) . . . . . . . . . . .158.  Security Considerations. . . . . . . . . . . . . . . . . . . .209.  Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . .2210. References . . . . . . . . . . . . . . . . . . . . . . . . . .2210.1. Normative References . . . . . . . . . . . . . . . . . .2210.2. Informative References . . . . . . . . . . . . . . . . .2311. Editors' Addresses . . . . . . . . . . . . . . . . . . . . . .2312. Full Copyright Statement . . . . . . . . . . . . . . . . . . .241.  The Internet-Standard Management Framework   For a detailed overview of the documents that describe the current   Internet-Standard Management Framework, please refer tosection 7 of   RFC 3410 [RFC3410].   Managed objects are accessed via a virtual information store, termed   the Management Information Base or MIB.  MIB objects are generally   accessed through the Simple Network Management Protocol (SNMP).   Objects in the MIB are defined using the mechanisms defined in the   Structure of Management Information (SMI).  This memo specifies a MIB   module that is compliant to the SMIv2, which is described in STD 58,RFC 2578 [RFC2578], STD 58,RFC 2579 [RFC2579] and STD 58,RFC 2580   [RFC2580].2.  Introduction   This memo defines a MIB module that can be used to convey management   information about desired network-wide Differentiated Services based   policy behavior.  This module is designed to integrate with the   Differentiated Services MIB module [RFC3289] in order to provide   template configurations for the Differentiated Services MIB module.   The MIB module defined in this memo (the DIFFSERV-CONFIG-MIB) may beHazewinkel & Partain        Standards Track                     [Page 2]

RFC 3747       Differentiated Services Configuration MIB      April 2004   used in combination with the Policy-based Management MIB module   [PMMIBDR], but that is not a requirement.  Without the Policy-based   Management MIB module, a management application must emulate behavior   provided by the Policy-based Management MIB using equivalent "low-   level" SNMP operations in normal manager/agent communication.   Together, this memo, [RFC3289], and [PMMIBDR] represent an instance   of an integrated architecture for both device-specific and network-   wide policy (configuration) management, which is fully integrated   with the Internet Standard Management Framework.   The Differentiated Services MIB module [RFC3289] operates on a device   level.  The MIB module in this memo, the DIFFSERV-CONFIG-MIB, creates   a coherent configuration management view as an umbrella over   [RFC3289].  That is, the DIFFSERV-CONFIG-MIB provides a conceptual   Application Program Interface (API) for configuration of the   Differentiated Services parameters.  Since the Differentiated   Services MIB module is able to maintain configuration information,   the DIFFSERV-CONFIG-MIB configuration API consists only of   configuration template information and the start of the so-called   functional datapath.3.  Other Documents   It is assumed that the reader is familiar with Differentiated   Services ([RFC2474] and [RFC2475]), the Policy-based Management MIB   ([PMMIBDR]), and "Configuring Networks and Devices With SNMP"   ([RFC3512]).  These documents include all of the necessary   terminology for understanding this memo.  However, note that use of   the MIB module in this memo does not require the use of [PMMIBDR].   [RFC3512] also provides an example MIB module which may help in   understanding the relationship between DIFFSERV-CONFIG-MIB and the   Differentiated Services MIB in [RFC3289].4.  Relationship to other MIBs   In this section, we describe the relationship of this MIB module to   other MIB modules.  The overall architecture used for policy   configuration management is described in [PMMIBDR].4.1.  The Policy-based Management MIB Module   [PMMIBDR] defines a MIB module that enables policy-based   configuration management of infrastructure using the Internet   Standard Management Framework.  The document includes a table for   configuring policies to be implemented, tables for storing the roles   of elements on a particular device, a table for representing the   capabilities of a device with respect to policy management, a tableHazewinkel & Partain        Standards Track                     [Page 3]

RFC 3747       Differentiated Services Configuration MIB      April 2004   for referencing elements affected by a policy, as well as other   infrastructure.  There is no requirement that [PMMIBDR] be used in   conjunction with the MIB module defined in this memo.   See [PMMIBDR] for a full description of the policy-based   configuration framework it provides.4.2.  The Differentiated Services MIB Module   The Differentiated Services MIB module [RFC3289] provides a common   set of managed objects useful for configuring Differentiated Services   parameters on a Differentiated Services capable device.  This is what   is referred to as instance-level configuration.  It is the alteration   of the instance-level information in that MIB module which may be   done using the objects in the MIB module defined in this memo.   It is recognized that vendors may include additional managed objects   in their devices (via vendor-specific MIB modules) for configuring   Differentiated Services parameters.  If a vendor chooses to use the   objects defined in this memo for configuration, the vendor should   provide additional managed objects in a similar approach as defined   for the Differentiated Services MIB module.   Since the managed objects of the Differentiated Services MIB   [RFC3289] are not directly associated with an instance (interface and   interface direction), the same managed objects can be used for   traffic treatment configuration templates in a Differentiated   Services capable device and can then be applied on multiple   instances.  Therefore, the tables as defined in the Differentiated   Services MIB can be used directly for template configuration   purposes.  Those tables are:      - diffServClfrTable      - diffServClfrElementTable      - diffServMultiFieldClfrTable      - diffServMeterTable      - diffServTBParamTable      - diffServActionTable      - diffServDscpMarkActTable      - diffServCountActTable      - diffServAlgDropTable      - diffServRandomDropTable      - diffServQTable      - diffServSchedulerTable      - diffServMinRateTable      - diffServMaxRateTableHazewinkel & Partain        Standards Track                     [Page 4]

RFC 3747       Differentiated Services Configuration MIB      April 2004   Readers familiar with the Differentiated Services MIB will notice   that these are all templates.  Only the diffServDataPathTable defines   a managed instance for Differentiated Services traffic treatment by   its indexes of the interface and its direction.  This also allows the   tables mentioned above to be used as a configuration template without   defining anything directly related to a managed instance.5.  The Differentiated Services Configuration MIB Module Design   The Differentiated Services Configuration MIB module (in this memo)   of the SNMP-based configuration management framework is positioned   between the Policy-based Management MIB module and the instance-   specific Differentiated Services MIB module as described above.   The MIB module found in this memo is designed to maintain   configuration templates for the Differentiated Services MIB [RFC3289]   module.  The module only has a template table that describes a   Differentiated Services traffic treatment by providing the starting   pointer of the functional datapath.  The templates represent a   specific configuration of traffic treatment in a functional datapath   of a Differentiated Services capable device.  To avoid duplication of   managed objects, the actual templates defining the functional   datapath are defined in the Differentiated Services MIB module.   These are also used for the management of the instances.  Therefore,   the implementation of the DIFFSERV-CONFIG-MIB module uses the tables   defined in the Differentiated Services MIB.  As soon as a   configuration is made active via the POLICY-MANAGEMENT-MIB or using   normal SNMP operations, the configuration defined within this MIB   module will be instantiated in the DIFFSERV-MIB.   Note that this is a conceptual process.  That is, the configuration   may not actually go through an API available in the subsystem which   implements the DIFFSERV-MIB module.  However, configuration via the   DIFFSERV-CONFIG-MIB module will alter the same instrumentation as the   DIFFSERV-MIB module whether it does it via the DIFFSERV-MIB module or   not.   The Differentiated Services Configuration MIB module only needs to   define a starting point of a traffic treatment configuration   template.  This table is similar to the diffServDataPathTable   [RFC3289].  However, it has a semantic difference in that the   diffServDataPathTable is associated with an instance (interface and   interface direction), whereas the diffServConfigTable in this memo is   not.Hazewinkel & Partain        Standards Track                     [Page 5]

RFC 3747       Differentiated Services Configuration MIB      April 2004   Unlike most MIB modules, changes to the managed objects in this MIB   module do not cause a change in the external/traffic behavior of the   device.  This MIB module is used to set up per-hop-behavior   configurations.  As soon as configurations are made active via the   POLICY-MANAGEMENT-MIB or SNMP operations, the configurations defined   within this MIB module will be instantiated in the DIFFSERV-MIB.   The only table in this MIB module is the diffServConfigTable, which   provides managed objects for registering traffic treatment   configurations used in differentiated services.  The sole purpose of   this table is to provide the starting point for a traffic treatment   configuration template.  The traffic treatment itself is performed by   functional datapath elements [RFC3289].6.  Template Cloning   The concept of the DIFFSERV-CONFIG-MIB is based on having traffic   treatment configuration templates.  The templates provide a set of   configuration values that provide a particular behavior, such as   Expedited Forwarding traffic treatment, in the functional datapath.   The template (or functional datapath) is similar to a linked list   from a starting point and each (functional datapath) element is   connected to the next element via the so-called next RowPointer.   The moment a template is activated (instantiated) on an interface and   its interface direction, the template needs to be copied/cloned, so   that the template remains as a template.  Note that the template is   logically "locked" through the cloning process.  That is, the   template cannot be changed part way through the cloning process.   With the exception of the indices, the cloned template will be   identical to the source template.   A literal copy/clone of the template is not possible, since the same   indices inside the element tables cannot be re-used.  The   instantiation process must therefore generate a new index for each   element.  As a result of this, the 'NEXT' pointers also need to be   updated.  Otherwise, those will point to the template.6.1.  An Approach to Template Cloning   What should a system containing Differentiated Services capabilities   and Differentiated Services configuration capabilities do   conceptually at the moment a template is activated on an interface?   The following approach should not be considered implementation   guidelines, but rather a conceptual explanation of what should be   done.Hazewinkel & Partain        Standards Track                     [Page 6]

RFC 3747       Differentiated Services Configuration MIB      April 2004      1) Get the index of the template to be activated      2) Get RowPointer (current) from            diffServConfigStart.index            of the diffServConfigTable      3) Check if RowPointer (current) exists      4) Logically "lock" the entry (current) pointed to by         RowPointer so that its values are not changed part way         through the cloning process.      5) Copy/Clone the entry (current) pointed to by RowPointer            a) Get a new index for the entry            b) Configure the new entry with the values               of the entry to be cloned            c) Update the NEXT pointer with a new RowPointer               that pointed to the previous entry that was copied               part of this template      6) Store RowPointer of cloned entry as (previous) in order to         update the NEXT pointer with the next cloned entry.      7) Get the RowPointer of the next element in the template         as (current)      8) If (current) RowPointer does not equal zeroDotZero go to 4      9) Logically "unlock" all the locked entries done by step 4).   If a configuration/template is activated via a means other than a   direct SNMP SET request, such as via the Policy-based Management MIB,   the handling of the activation and potential error response code must   be provided via that mechanism.  If a configuration/template is   activated using SNMP SET requests, an accurate error response value   must be returned.  For example, if a configuration/template has   inconsistent values, the SNMP SET should return an error.  Whether   the configuration is already finished is not of direct importance,   since the SNMP SET response must be accurate.  On systems where the   activation may take a long time, a response may be given prior to   completion, but extra mechanisms must be provided to detect any   errors.6.2.  Example   This section provides an example of the process described in the   previous section.  This example will show a Differentiated Services   capable incoming (ingress) interface that only counts the traffic   stream.  Then, with the policy-based configuration concept as defined   in this document and in [PMMIBDR], a traffic marking configuration   will be applied.  The example will walk the reader through all of the   steps involved in this process.  Again, the use of [PMMIBDR] is   simply an example and is not required.Hazewinkel & Partain        Standards Track                     [Page 7]

RFC 3747       Differentiated Services Configuration MIB      April 2004      NOTE WELL:  For brevity and clarity, the example does not always      show the complete entry (row) of a table.  The only objects shown      are those needed for creating the row pointers to the next      functional datapath element or needed to provide information about      the specific parameters of the functional datapath elements.  The      column named 'INDEX' always defines the complete index as defined      for the associated entry.  In some cases, this is a combined index      of multiple components.  Therefore, the names of the columns are      omitted.      Also note that the values Assured Forwarding and Expedited      Forwarding are abstracted as DSCP(AF) and DSCP(EF) (respectively)      or simply as AF and EF.  For the actual values refer to [RFC3289].6.2.1.  The Initial Situation   The initial configuration is the existing configuration of an ingress   interface.      +------------------------------------------------------------+      |   ingress functional datapath                              |      |                        +----------+                        |   -->|----------->----------->| count    |----------->----------->|-->      |                        +----------+                        |      +------------------------------------------------------------+   This figure depicts a simple traffic treatment functional datapath   for an ingress interface.  The functional datapath only consists of a   count action.   Within the DIFFSERV-MIB, this would be instantiated as follows.  Note   that RowPointer objects must point to the first accessible columnar   object in the conceptual row.  Thus, while perhaps more instructive   to use the index value for the RowPointer object's value (e.g.,   diffServCountActId.1) in the example, it would nonetheless be   incorrect, and the first accessible columnar object has been used as   should be done (e.g., diffServCountActOctets.1).   diffServDataPathTable   +-----------------+-----------------------------+--   | INDEX           | diffServDataPathStart       |   +-----------------+-----------------------------+--   | ifIndex.ingress | diffServActionNext.1        |   +-----------------+-----------------------------+--Hazewinkel & Partain        Standards Track                     [Page 8]

RFC 3747       Differentiated Services Configuration MIB      April 2004   diffServActionTable   +-------+--------------------+-------------------------+--   | INDEX | diffServActionNext |diffServActionSpecific   |   +-------+--------------------+-------------------------+--   | 1     | 0.0                |diffServCountActOctets.1 |   +-------+--------------------+-------------------------+--   diffServCountActTable   +-------+------------------------+--   | INDEX | diffServCountActOctets |   +-------+------------------------+--   | 1     |                        |   +-------+------------------------+--6.2.2.  The Configuration Template   The following provides an example of a policy configuration in which   traffic is classified by a specific IP filter, that results in two   classifiers (one for the IP filter and one for match all).  Both   streams are then metered, marked, and counted.  This is an example of   usage on the edge (an ingress interface) of a Differentiated Services   domain that wants to have Expedited Forwarding and Assured Forwarding   marked traffic within the Differentiated Services domain.   +------------------------------------------------------------+   |   ingress functional datapath                              |   |   +------------+   +-------+   +---------+   +---------+   |   |   |            |   |       |   | action: |   | action: |   |-->|-->| classifier |-->| meter |-->| mark EF |-->| count   |-->|----->   |   | match <IP> |   |       |   |         |   |         |   |   |   +------------+   +-------+   +---------+   +---------+   |   |         |                 \                                |   |         |                  \      +---------+              |   |         |                   \     | action: |              |routing   |         |                    * -->| dropper |              |core   |         |                   /     |         |              |   |         |                  /      +---------+              |   |         V                 /                                |   |   +------------+   +-------+   +---------+   +---------+   |   |   |            |   |       |   | action: |   | action: |   |   |   | classifier |-->| meter |-->| mark AF |-->| count   |-->|----->   |   | match all  |   |       |   |         |   |         |   |   |   +------------+   +-------+   +---------+   +---------+   |   +------------------------------------------------------------+   This figure depicts a policy configuration for ingress traffic   treatment in a Differentiated Services capable device.  TheHazewinkel & Partain        Standards Track                     [Page 9]

RFC 3747       Differentiated Services Configuration MIB      April 2004   configuration is represented as follows in the DIFFSERV-CONFIG-MIB   module and the DIFFSERV-MIB module.   Note that the original (existing) traffic treatment described in   6.2.1 is also in the tables.   Note also that in the diffServDscpMarkActTable, DSCP(EF) represents   the DSCP value for Expedited Forwarding and DSCP(AF) represents the   DSCP value for Assured Forwarding. diffServConfigTable (in the MIB module in this memo) +-------+-------------------------+---------------------------+-- | INDEX | diffServConfigStart     | diffServConfigDescr       | +-------+-------------------------+---------------------------+-- | "foo" | diffServClfrStorage.1   | Example traffic treatment | +-------+-------------------------+---------------------------+-- diffServClfrTable +-------+---------------------+--------------------+ | INDEX | diffServClfrStorage | diffServClfrStatus | +-------+---------------------+--------------------+ | 1     |                     |                    | +-------+---------------------+--------------------+ diffServClfrElementTable (shares index with diffServClfrTable) +-------+---------------------------+-------------------------------+-- | INDEX | diffServClfrElementNext   | diffServClfrElementPrecedence | +-------+---------------------------+-------------------------------+-- | 1.1   |diffServMeterSucceedNext.1 | 1                             | | 1.2   |diffServMeterSucceedNext.2 | 2                             | +-------+---------------------------+-------------------------------+-- diffServMeterTable +-------+--------------------------+-----------------------+-- | INDEX | diffServMeterSucceedNext |diffServMeterFailNext  | +-------+--------------------------+-----------------------+-- | 1     | diffServActionNext.2     | diffServAlgDropType.1 | | 2     | diffServActionNext.3     | diffServAlgDropType.1 | +-------+--------------------------+-----------------------+--Hazewinkel & Partain        Standards Track                    [Page 10]

RFC 3747       Differentiated Services Configuration MIB      April 2004 diffServActionTable +-------+----------------------+----------------------------+-- | INDEX | diffServActionNext   | diffServActionSpecific     | +-------+----------------------+----------------------------+-- | 1     | 0.0                  | diffServCountActOctets.1   | | 2     | diffServActionNext.4 | diffServDscpMarkActDscp.EF | | 3     | diffServActionNext.5 | diffServDscpMarkActDscp.AF | | 4     | 0.0                  | diffServCountActOctets.2   | | 5     | 0.0                  | diffServCountActOctets.3   | +-------+----------------------+----------------------------+-- diffServCountActTable +-------+------------------------+-- | INDEX | diffServCountActOctets | +-------+------------------------+-- | 1     |                        | | 2     |                        | | 3     |                        | +-------+------------------------+-- diffServAlgDropTable +-------+---------------------+-------------------------+-- | INDEX | diffServAlgDropType | diffServAlgDropSpecific | +-------+---------------------+-------------------------+-- | 1     | alwaysDrop(5)       | 0.0                     | +-------+---------------------+-------------------------+-- diffServDscpMarkActTable +-------------------------+ | diffServDscpMarkActDscp | +-------------------------+ | DSCP(EF)                | | DSCP(AF)                | +-------------------------+6.2.3.  Applying the Template   Now we have the original ingress interface configuration and the   policy configuration we want to apply to the actual interface.   The example policy must provide the required Differentiated Services   traffic treatment to all interfaces used by system administrators.   The traffic treatment required is described in 6.2.2 above.   Therefore, we have the following example policy which is configured   via the POLICY-BASED-MANAGEMENT-MIB module (see [PMMIBDR]):   if ( roleMatch("Administrator") )Hazewinkel & Partain        Standards Track                    [Page 11]

RFC 3747       Differentiated Services Configuration MIB      April 2004   then      /*       * The $0 gets the "element" returned from the previous       * statement.  the .1 at the end is the ingress interface       * This sets, for example, diffServDataPathStart.3.1 to be       * "diffServConfigStart.3.f.o.o" if interface 3 has the role       * "Administrator".       */      setVar("diffServDataPathStart.$0.1",              "diffServConfigStart.3.f.o.o", Oid)   For our purposes, we only apply this on the inbound (ingress)   direction of the interface.   Note that although object descriptors are used in this PolicyScript   example, the object identifiers must be used in the running script.   For more information on policies and their syntax refer to [PMMIBDR].   The following tables in this section provide the cloned entries in   the tables of the DIFFSERV-MIB module.  All tables may have columns   that contain contents or administrative objects that are not shown.   These columns do not determine a function in the datapath and they   are not shown for clarity of the cloning mechanism.   Note that the original (existing) traffic treatment of 6.2.1 and   6.2.2 are also in the tables.diffServConfigTable+-------+-------------------------+---------------------------+--| INDEX | diffServConfigStart     | diffServConfigDescr       |+-------+-------------------------+---------------------------+--| "foo" | diffServClfrStorage.1   | Example traffic treatment |+-------+-------------------------+---------------------------+--diffServDataPathTable+-----------------+-----------------------------+--| INDEX           | diffServDataPathStart       |+-----------------+-----------------------------+--| ifIndex.ingress | diffServActionNext.2        |+-----------------+-----------------------------+--Hazewinkel & Partain        Standards Track                    [Page 12]

RFC 3747       Differentiated Services Configuration MIB      April 2004diffServClfrTable+-------+---------------------+--------------------+| INDEX | diffServClfrStorage | diffServClfrStatus |+-------+---------------------+--------------------+| 1     |                     |                    || 2     |                     |                    |+-------+---------------------+--------------------+diffServClfrElementTable+-------+----------------------------+-------------------------------+--| INDEX | diffServClfrElementNext    | diffServClfrElementPrecedence |+-------+----------------------------+-------------------------------+--| 1.1   | diffServMeterSucceedNext.1 | 1                             || 1.2   | diffServMeterSucceedNext.2 | 2                             || 2.3   | diffServMeterSucceedNext.3 | 1                             || 2.4   | diffServMeterSucceedNext.4 | 2                             |+-------+----------------------------+-------------------------------+--diffServMeterTable+-------+--------------------------+-----------------------+--| INDEX | diffServMeterSucceedNext | diffServMeterFailNext |+-------+--------------------------+-----------------------+--| 1     | diffServActionNext.2     | diffServAlgDropType.1 || 2     | diffServActionNext.3     | diffServAlgDropType.1 || 3     | diffServActionNext.6     | diffServAlgDropType.2 || 4     | diffServActionNext.7     | diffServAlgDropType.2 |+-------+--------------------------+-----------------------+--diffServActionTable+-------+----------------------+----------------------------+--| INDEX | diffServActionNext   | diffServActionSpecific     |+-------+----------------------+----------------------------+--| 1     | 0.0                  | diffServCountActOctets.1   || 2     | diffServActionNext.4 | diffServDscpMarkActDscp.EF || 3     | diffServActionNext.5 | diffServDscpMarkActDscp.AF || 4     | 0.0                  | diffServCountActOctets.2   || 5     | 0.0                  | diffServCountActOctets.3   || 6     | diffServActionNext.8 | diffServDscpMarkActDscp.EF || 7     | diffServActionNext.9 | diffServDscpMarkActDscp.AF || 8     | 0.0                  | diffServCountActOctets.4   || 9     | 0.0                  | diffServCountActOctets.5   |+-------+----------------------+----------------------------+--Hazewinkel & Partain        Standards Track                    [Page 13]

RFC 3747       Differentiated Services Configuration MIB      April 2004diffServCountActTable+-------+------------------------+--| INDEX | diffServActCountOctets |+-------+------------------------+--| 1     |                        || 2     |                        || 3     |                        || 4     |                        || 5     |                        |+-------+------------------------+--diffServAlgDropTable+-------+---------------------+-------------------------+--| INDEX | diffServAlgDropType | diffServAlgDropSpecific |+-------+---------------------+-------------------------+--| 1     | alwaysDrop(5)       | 0.0                     |+-------+---------------------+-------------------------+--diffServDscpMarkActTable+-------------------------+| diffServDscpMarkActDscp |+-------------------------+| DSCP(EF)                || DSCP(AF)                |+-------------------------+   As one can see in the example, the main elements from which a   functional datapath is constructed are duplicated/copied/cloned.   That process is needed in order to preserve the policy configuration   for reuse at a later time.   It is up to the SNMP agent to keep track of which network interfaces   are under policy control and which policy rules are being used.  This   avoids duplication of policy enforcement.  How the agent does this is   an implementation issue.   One can see that the old functional datapath configurations stay in   the MIB module tables.  It is up to the SNMP agent implementation to   decide whether to delete stale entries or keep them.  Garbage   collection of stale entries is an implementation issue.6.2.4.  Applying the Template Using SNMP Messages   In this section, the above example is explained by using SNMP   communication between the SNMP "manager" and the SNMP "agent".Hazewinkel & Partain        Standards Track                    [Page 14]

RFC 3747       Differentiated Services Configuration MIB      April 2004   In order to apply the template to all interfaces that have a role   match of "Administrator," the SNMP manager must have a list of the   roles of the interface.  This means the SNMP manager must do an   SNMP-SET for all those interfaces.  This is expressed in the   following pseudo code function.   set_template_if_administrator_interface(            <interface_list>, <template_name>   ) {      template_oid = SNMP-GET("diffServConfigStart.<template_name>");      foreach interface (<ifRole_list>) {         if (interface.role == "Administrator") {            SNMP-SET("diffServDataPathStart.$interface.1",                  Oid, template_oid);         }      }   }   For example, on a system with 3 interfaces, the following list would   be known to the manager.  The first value indicates the interface   number (ifIndex) and the second value is its role.   interface_list IF_LIST = {       { 1, ... , "Administrator", ... },       { 2, ... , "User", ... },       { 3, ... , "Administrator", ... } }   This will result in the communication between a manager and agent of   1 SNMP-GET and 2 SNMP-SETs:   -  SNMP-GET("diffServConfigStart.3.f.o.o")   -  SNMP-SET("diffServDataPathStart.1.1", Oid, "diffServActionNext.1")   -  SNMP-SET("diffServDataPathStart.3.1", Oid, "diffServActionNext.1")7.  Managed Objects Definitions (MIB Module)DIFFSERV-CONFIG-MIB DEFINITIONS ::= BEGIN    IMPORTS    OBJECT-TYPE, MODULE-IDENTITY,    zeroDotZero, mib-2            FROM SNMPv2-SMI          -- [RFC2578]    RowStatus, StorageType,    RowPointer, DateAndTime       FROM SNMPv2-TC           -- [RFC2579]    MODULE-COMPLIANCE,    OBJECT-GROUP                  FROM SNMPv2-CONF         -- [RFC2580]Hazewinkel & Partain        Standards Track                    [Page 15]

RFC 3747       Differentiated Services Configuration MIB      April 2004    SnmpAdminString               FROM SNMP-FRAMEWORK-MIB; -- [RFC3411]diffServConfigMib MODULE-IDENTITY    LAST-UPDATED "200401220000Z" -- 22 January 2004    ORGANIZATION "SNMPCONF WG"    CONTACT-INFO       "SNMPCONF Working Grouphttp://www.ietf.org/html.charters/snmpconf-charter.html        WG mailing list: snmpconf@snmp.com        Editors:        Harrie Hazewinkel        I.Net        via Darwin 85        20019 - Settimo Milanese (MI)        Italy        EMail: harrie@inet.it        David Partain        Ericsson AB        P.O. Box 1248        SE-581 12 Linkoping        Sweden        E-mail: David.Partain@ericsson.com"    DESCRIPTION        "This MIB module contains differentiated services        specific managed objects to perform higher-level        configuration management.  This MIB allows policies        to use 'templates' to instantiate Differentiated        Services functional datapath configurations to        be assigned (associated with an interface and        direction) when a policy is activated.        Copyright (C) The Internet Society (2004).  This version        of this MIB module is part ofRFC 3747;  see the RFC        itself for full legal notices."    REVISION "200401220000Z" -- 22 January 2004    DESCRIPTION        "Initial version published asRFC 3747"    ::= { mib-2 108 }diffServConfigMIBObjects OBJECT IDENTIFIER ::= { diffServConfigMib 1 }diffServConfigMIBConformance OBJECT IDENTIFIER ::=                                               { diffServConfigMib 2 }---- The Differentiated Services configuration objects--Hazewinkel & Partain        Standards Track                    [Page 16]

RFC 3747       Differentiated Services Configuration MIB      April 2004diffServConfigTable OBJECT-TYPE    SYNTAX       SEQUENCE OF DiffServConfigEntry    MAX-ACCESS   not-accessible    STATUS       current    DESCRIPTION       "A table which defines the various per-hop-behaviors       for which the system has default 'templates'."    ::= { diffServConfigMIBObjects 2 }diffServConfigEntry OBJECT-TYPE    SYNTAX       DiffServConfigEntry    MAX-ACCESS   not-accessible    STATUS       current    DESCRIPTION       "An entry defining a per-hop-behavior.  Each entry in       this table combines the various parameters (entries)       into a specific per-hop-behavior.  Entries in this       table might be defined by a vendor (pre-configured)       or defined by a management application."    INDEX { diffServConfigId }    ::= { diffServConfigTable 1 }DiffServConfigEntry ::= SEQUENCE {    diffServConfigId           SnmpAdminString,    diffServConfigDescr        SnmpAdminString,    diffServConfigOwner        SnmpAdminString,    diffServConfigLastChange   DateAndTime,    diffServConfigStart        RowPointer,    diffServConfigStorage      StorageType,    diffServConfigStatus       RowStatus}diffServConfigId OBJECT-TYPE    SYNTAX         SnmpAdminString (SIZE(1..116))    MAX-ACCESS     not-accessible    STATUS         current    DESCRIPTION      "A unique id for the per-hop-behavior policy for at       least the SNMP agent.  For ease of administration the       value may be unique within an administrative domain,       but this is not required.       The range of up to 116 octets is chosen to stay within       the SMI limit of 128 sub-identifiers in an object       identifier."    ::= { diffServConfigEntry 1 }diffServConfigDescr OBJECT-TYPEHazewinkel & Partain        Standards Track                    [Page 17]

RFC 3747       Differentiated Services Configuration MIB      April 2004    SYNTAX         SnmpAdminString    MAX-ACCESS     read-create    STATUS         current    DESCRIPTION       "A human-readable description to identify this defined       per-hop-behavior.  Note that this is an SnmpAdminString,       which permits UTF-8 strings.  An administratively assigned       identifier for a template that would be unique within       an administrative domain.  It is up to the management       applications to agree how these are assigned within the       administrative domain.  Once a description, such as       'EF' is assigned, that has a certain set of parameters       that achieve 'EF' from box to box. Management       application code or script code can then scan       the table to find the proper template and then       assign it."    ::= { diffServConfigEntry 2 }diffServConfigOwner OBJECT-TYPE    SYNTAX         SnmpAdminString    MAX-ACCESS     read-create    STATUS         current    DESCRIPTION       "The owner who created this entry."    ::= { diffServConfigEntry 3 }diffServConfigLastChange OBJECT-TYPE    SYNTAX         DateAndTime    MAX-ACCESS     read-only    STATUS         current    DESCRIPTION       "The date and time when this entry was last changed."    ::= { diffServConfigEntry 4 }diffServConfigStart OBJECT-TYPE    SYNTAX         RowPointer    MAX-ACCESS     read-create    STATUS         current    DESCRIPTION       "The pointer to a functional datapath configuration template as       set up in the DIFFSERV-MIB.  This RowPointer should       point to an instance of one of:         diffServClfrEntry         diffServMeterEntry         diffServActionEntry         diffServAlgDropEntry         diffServQEntryHazewinkel & Partain        Standards Track                    [Page 18]

RFC 3747       Differentiated Services Configuration MIB      April 2004       A value of zeroDotZero in this attribute indicates no       further Diffserv treatment is performed on traffic of       this functional datapath.  This also means that the       template described by this row is not defined.       If the row pointed to does not exist, the treatment       is as if this attribute contains a value of zeroDotZero."    REFERENCE       "Differentiated Services MIB module"    DEFVAL { zeroDotZero }    ::= { diffServConfigEntry 5 }diffServConfigStorage OBJECT-TYPE    SYNTAX         StorageType    MAX-ACCESS     read-create    STATUS         current    DESCRIPTION       "The type of storage used for this row.       Since an entry in this table serves as a starting       point for a configuration, it is recommended that       all entries comprising the configuration started by       diffServConfigStart follow the storage type of this       entry.  Otherwise, after agent reboots a configuration       may differ.  It may very well be that the agent is       not capable of detecting such changes and therefore,       the management application should verify the correct       configuration after a reboot.  Rows with a StorageType       of 'permanent' do not need to allow write access to       any of the columnar objects in that row."    DEFVAL { nonVolatile }    ::= { diffServConfigEntry 6 }diffServConfigStatus OBJECT-TYPE    SYNTAX         RowStatus    MAX-ACCESS     read-create    STATUS         current    DESCRIPTION       "RowStatus object used for creation and deletion of       rows in this table.  All writable objects in this row       may be modified at any time."    DEFVAL { notInService }    ::= { diffServConfigEntry 7 }---- MIB Compliance statements.--Hazewinkel & Partain        Standards Track                    [Page 19]

RFC 3747       Differentiated Services Configuration MIB      April 2004diffServConfigMIBCompliances   OBJECT IDENTIFIER ::= { diffServConfigMIBConformance 1 }diffServConfigMIBGroups   OBJECT IDENTIFIER ::= { diffServConfigMIBConformance 2 }diffServConfigMIBFullCompliance MODULE-COMPLIANCE    STATUS       current    DESCRIPTION       "The full compliance for this MIB module.       For this compliance level the 'diffServMIBFullCompliance'       must be met, since this MIB module depends on it in order       to provide the configuration entries.       "    MODULE  -- This module    MANDATORY-GROUPS {  diffServConfigMIBConfigGroup }    OBJECT diffServConfigStatus    SYNTAX RowStatus { active(1) }    WRITE-SYNTAX RowStatus { createAndGo(4), destroy(6) }    DESCRIPTION       "Support for createAndWait and notInService is not required."    ::= { diffServConfigMIBCompliances 1 }diffServConfigMIBConfigGroup OBJECT-GROUP    OBJECTS {  diffServConfigDescr,               diffServConfigOwner,               diffServConfigLastChange,               diffServConfigStart,               diffServConfigStorage,               diffServConfigStatus    }    STATUS current    DESCRIPTION       "The per-hop-behavior Group defines the MIB objects that       describe the configuration template for the per-hop-behavior."    ::= { diffServConfigMIBGroups 1 }END8.  Security Considerations   There are a number of management objects defined in this MIB module   with a MAX-ACCESS clause of read-write and/or read-create.  Such   objects may be considered sensitive or vulnerable in some network   environments.  The support for SET operations in a non-secure   environment without proper protection can have a negative effect on   network operations.  These managed objects are:Hazewinkel & Partain        Standards Track                    [Page 20]

RFC 3747       Differentiated Services Configuration MIB      April 2004   -  The diffServConfigDescr, diffServConfigOwner, and      diffServConfigStatus are not security sensitive since these three      objects do not affect any direct operational behavior of a      diffserv capable device.   -  Unauthorized change of the diffServConfigStart could lead to a      different configuration, and the 'changed' configuration could      lead to different traffic treatment for the diffserv capable      device than desired.   -  Unauthorized change of the diffServConfigStorage could lead to      unknown behavior of the diffserv capable device after a reboot of      the SNMP agent.  This may be caused by 'not having saved changes      of the configuration' or unavailable configurations.   In addition, the managed objects of the DIFFSERV-MIB are also   security sensitive, since unauthorized changes may cause   configuration changes.  For more detail, refer to [RFC3289].   Allowing read access to objects in this MIB module is generally not   considered sensitive, as read access only provides information that a   template exists.  This is due to the fact that the managed objects   that actually instantiate the template are in the DIFFSERV-MIB   [RFC3289].  However, in environments where the template description   (diffServConfigDescr) or owner (diffServConfigOwner) is considered   sensitive information, appropriate access control should be exercised   for these objects.   SNMP versions prior to SNMPv3 did not include adequate security.   Even if the network itself is secure (for example by using IPSec),   there is no control as to who on the secure network is allowed to   access and GET/SET (read/change/create/delete) the objects in this   MIB module.   It is RECOMMENDED that implementers consider the security features as   provided by the SNMPv3 framework (see[RFC3410], section 8),   including full support for the SNMPv3 cryptographic mechanisms (for   authentication and privacy).   Further, deployment of SNMP versions prior to SNMPv3 is NOT   RECOMMENDED.  Instead, deployment of SNMPv3 with cryptographic   security enabled is RECOMMENDED.  It is then a customer/operator   responsibility to ensure that the SNMP entity giving access to an   instance of this MIB module is properly configured to give access to   the objects only to those principals (users) that have legitimate   rights to GET or SET (change/create/delete) them.Hazewinkel & Partain        Standards Track                    [Page 21]

RFC 3747       Differentiated Services Configuration MIB      April 20049.  Acknowledgments   The editors gratefully acknowledge the significant contributions to   this work made by several members of both the SNMPCONF and DiffServ   working groups.10.  References10.1.  Normative References   [RFC2578] McCloghrie, K., Perkins, D. and J. Schoenwaelder,             "Structure of Management Information Version 2 (SMIv2)",             STD 58,RFC 2578, April 1999.   [RFC2579] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Textual             Conventions for SMIv2", STD 58,RFC 2579, April 1999.   [RFC2580] McCloghrie, K., Perkins, D. and J. Schoenwaelder,             "Conformance Statements for SMIv2", STD 58,RFC 2580, April             1999.   [RFC3289] Baker, F., Chan, K. and A. Smith, "Management Information             Base for the Differentiated Services Architecture",RFC3289, May 2002.   [RFC3411] Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture             for Describing Simple Network Management Protocol (SNMP)             Management Frameworks", STD 62,RFC 3411, December 2002.Hazewinkel & Partain        Standards Track                    [Page 22]

RFC 3747       Differentiated Services Configuration MIB      April 200410.2.  Informative References   [RFC3410] Case, J., Mundy, R., Partain, D. and B. Stewart,             "Introduction and Applicability Statements for Internet-             Standard Management Framework",RFC 3410, December 2002.   [RFC2474] Nichols, K., Blake, S., Baker, F. and D. Black, "Definition             of the Differentiated Services Field (DS Field) in the IPv4             and IPv6 Headers",RFC 2474, December 1998.   [RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z. and             W. Weiss, "An Architecture for Differentiated Services",RFC 2475, December 1998.   [RFC3512] MacFaden, M., Partain, D., Saperia, J. and W. Tackabury,             "Configuring Networks and Devices with Simple Network             Management Protocol (SNMP)",RFC 3512, April 2003.   [PMMIBDR] Waldbusser, S., Saperia, J. and T. Hongal, "Policy-based             Management MIB", Work in Progress.11.  Editors' Addresses   Harrie Hazewinkel   I.Net   via Darwin 85   20019 - Settimo Milanese (MI)   Italy   EMail: harrie@inet.it   David Partain   Ericsson AB   P.O. Box 1248   SE-581 12 Linkoping   Sweden   EMail: David.Partain@ericsson.comHazewinkel & Partain        Standards Track                    [Page 23]

RFC 3747       Differentiated Services Configuration MIB      April 200412.  Full Copyright Statement   Copyright (C) The Internet Society (2004).  This document is subject   to the rights, licenses and restrictions contained inBCP 78 and   except as set forth therein, the authors retain all their rights.   This document and the information contained herein are provided on an   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET   ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,   INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE   INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.Intellectual Property   The IETF takes no position regarding the validity or scope of any   Intellectual Property Rights or other rights that might be claimed to   pertain to the implementation or use of the technology described in   this document or the extent to which any license under such rights   might or might not be available; nor does it represent that it has   made any independent effort to identify any such rights.  Information   on the procedures with respect to rights in RFC documents can be   found inBCP 78 andBCP 79.   Copies of IPR disclosures made to the IETF Secretariat and any   assurances of licenses to be made available, or the result of an   attempt made to obtain a general license or permission for the use of   such proprietary rights by implementers or users of this   specification can be obtained from the IETF on-line IPR repository athttp://www.ietf.org/ipr.   The IETF invites any interested party to bring to its attention any   copyrights, patents or patent applications, or other proprietary   rights that may cover technology that may be required to implement   this standard.  Please address the information to the IETF at ietf-   ipr@ietf.org.Acknowledgement   Funding for the RFC Editor function is currently provided by the   Internet Society.Hazewinkel & Partain        Standards Track                    [Page 24]

[8]ページ先頭

©2009-2025 Movatter.jp