IP Forwarding Table MIB
RFC 1354

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• 05

Network Working Group                                           F. Baker
Request For Comments: 1354                                           ACC
                                                               July 1992

                        IP Forwarding Table MIB

Status of this Memo

   This RFC specifies an IAB standards track protocol for the Internet
   community, and requests discussion and suggestions for improvements.
   Please refer to the current edition of the "IAB Official Protocol
   Standards" for the standardization state and status of this protocol.
   Distribution of this memo is unlimited.

Abstract

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in TCP/IP-based internets.
   In particular, it defines objects for managing routes in the IP
   Internet.

   It is proposed that the ipRouteTable defined by MIB-II (RFC 1213) be
   deprecated and replaced with this table.  This adds the ability to
   set or display multi-path routes, and varying routes by network
   management policy.

Table of Contents

   1. The Network Management Framework ............................    1
   2. Objects .....................................................    2
   2.1 Format of Definitions ......................................    2
   3. Overview ....................................................    3
   3.1 Structure of MIB ...........................................    3
   4. Definitions .................................................    4
   4.1 IP Forwarding Table ........................................    4
   5. Acknowledgements ............................................   11
   6. References ..................................................   11
   7. Security Considerations........................................ 12
   8. Author's Address............................................... 12

1.  The Network Management Framework

   The Internet-standard Network Management Framework consists of three
   components.  They are:

   RFC 1155 which defines the SMI, the mechanisms used for describing
   and naming objects for the purpose of management.  RFC 1212 defines a

Baker                                                           [Page 1]
RFC 1354                IP Forwarding Table MIB                July 1992

   more concise description mechanism, which is wholly consistent with
   the SMI.

   RFC 1156 which defines MIB-I, the core set of managed objects for the
   Internet suite of protocols.  RFC 1213 defines MIB-II, an evolution
   of MIB-I based on implementation experience and new operational
   requirements.

   RFC 1157 which defines the SNMP, the protocol used for network access
   to managed objects.

   The Framework permits new objects to be defined for the purpose of
   experimentation and evaluation.

2.  Objects

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  Objects in the MIB are
   defined using the subset of Abstract Syntax Notation One (ASN.1) [7]
   defined in the SMI.  In particular, each object has a name, a syntax,
   and an encoding.  The name is an object identifier, an
   administratively assigned name, which specifies an object type.  The
   object type together with an object instance serves to uniquely
   identify a specific instantiation of the object.  For human
   convenience, we often use a textual string, termed the OBJECT
   DESCRIPTOR, to also refer to the object type.

   The syntax of an object type defines the abstract data structure
   corresponding to that object type.  The ASN.1 language is used for
   this purpose.  However, the SMI [3] purposely restricts the ASN.1
   constructs which may be used.  These restrictions are explicitly made
   for simplicity.

   The encoding of an object type is simply how that object type is
   represented using the object type's syntax.  Implicitly tied to the
   notion of an object type's syntax and encoding is how the object type
   is represented when being transmitted on the network.

   The SMI specifies the use of the basic encoding rules of ASN.1 [8],
   subject to the additional requirements imposed by the SNMP.

2.1.  Format of Definitions

   Section 4 contains contains the specification of all object types
   contained in this MIB module.  The object types are defined using the
   conventions defined in the SMI, as amended by the extensions
   specified in [9].

Baker                                                           [Page 2]
RFC 1354                IP Forwarding Table MIB                July 1992

3.  Overview

3.1.  Structure of MIB

   The IP Forwarding Table is quite analogous to the older ipRoute
   Table.  The principal differences are:

      (1)  It is somewhat re-organized, for aesthetic reasons,

      (2)  It has the Next Hop Autonomous System Number, useful
           primarily to the administrators of regional networks,

      (3)  It is instanced by Policy and Next Hop as well as by