IP Version 6 Management Information Base for the Transmission Control Protocol
RFC 2452

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Network Working Group                                      M. Daniele
Request for Comments: 2452                Compaq Computer Corporation
Category: Standards Track                               December 1998

               IP Version 6 Management Information Base
                 for the Transmission Control Protocol

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (1998).  All Rights Reserved.

Abstract

   This document is one in the series of documents that define various
   MIB objects for IPv6.  Specifically, this document is the MIB module
   which defines managed objects for implementations of the Transmission
   Control Protocol (TCP) over IP Version 6 (IPv6).

   This document also recommends a specific policy with respect to the
   applicability of RFC 2012 for implementations of IPv6.  Namely, that
   most of managed objects defined in RFC 2012 are independent of which
   IP versions underlie TCP, and only the TCP connection information is
   IP version-specific.

   This memo defines an experimental portion of the Management
   Information Base (MIB) for use with network management protocols in
   IPv6-based internets.

1.  Introduction

   A management system contains: several (potentially many) nodes, each
   with a processing entity, termed an agent, which has access to
   management instrumentation; at least one management station; and, a
   management protocol, used to convey management information between
   the agents and management stations.  Operations of the protocol are
   carried out under an administrative framework which defines
   authentication, authorization, access control, and privacy policies.

Daniele                     Standards Track                     [Page 1]
RFC 2452                    TCP MIB for IPv6               December 1998

   Management stations execute management applications which monitor and
   control managed elements.  Managed elements are devices such as
   hosts, routers, terminal servers, etc., which are monitored and
   controlled via access to their management information.

   Management information is viewed as a collection of managed objects,
   residing in a virtual information store, termed the Management
   Information Base (MIB).  Collections of related objects are defined
   in MIB modules.  These modules are written using a subset of OSI's
   Abstract Syntax Notation One (ASN.1) [1], termed the Structure of
   Management Information (SMI) [2].

2.  Overview

   This document is one in the series of documents that define various
   MIB objects, and statements of conformance, for IPv6.  This document
   defines the required instrumentation for implementations of TCP over
   IPv6.

3.  Transparency of IP versions to TCP

   The fact that a particular TCP connection uses IPv6 as opposed to
   IPv4, is largely invisible to a TCP implementation.  A "TCPng" did
   not need to be defined, implementations simply need to support IPv6
   addresses.

   As such, the managed objects already defined in [TCP MIB] are
   sufficient for managing TCP in the presence of IPv6.  These objects
   are equally applicable whether the managed node supports IPv4 only,
   IPv6 only, or both IPv4 and IPv6.

   For example, tcpActiveOpens counts "The number of times TCP
   connections have made a direct transition to the SYN-SENT state from
   the CLOSED state", regardless of which version of IP is used between
   the connection endpoints.

   Stated differently, TCP implementations don't need separate counters
   for IPv4 and for IPv6.

4.  Representing TCP Connections

   The exception to the statements in section 3 is the tcpConnTable.
   Since IPv6 addresses cannot be represented with the IpAddress syntax,
   not all TCP connections can be represented in the tcpConnTable
   defined in [TCP MIB].

Daniele                     Standards Track                     [Page 2]
RFC 2452                    TCP MIB for IPv6               December 1998

   This memo defines a new, separate table to represent only those TCP
   connections between IPv6 endpoints.  TCP connections between IPv4
   endpoints continue to be represented in tcpConnTable [TCP MIB].  (It
   is not possible to establish a TCP connection between an IPv4
    endpoint and an IPv6 endpoint.)

   A different approach would have been to define a new table to
   represent all TCP connections regardless of IP version.  This would
   require changes to [TCP MIB] and hence to existing (IPv4-only) TCP
   implementations.  The approach suggested in this memo has the
   advantage of leaving IPv4-only implementations intact.