rfc2452.txt

RFC 的详细文档！

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.

   It is assumed that the objects defined in this memo will eventually
   be defined in an update to [TCP MIB].  For this reason, the module
   identity is assigned under the experimental portion of the MIB.

5.  Conformance

   This memo contains conformance statements to define conformance to
   this MIB for TCP over IPv6 implementations.

6.  Definitions

IPV6-TCP-MIB DEFINITIONS ::= BEGIN

IMPORTS
   MODULE-COMPLIANCE, OBJECT-GROUP      FROM SNMPv2-CONF
   MODULE-IDENTITY, OBJECT-TYPE,
   mib-2, experimental                  FROM SNMPv2-SMI
   Ipv6Address, Ipv6IfIndexOrZero       FROM IPV6-TC;

ipv6TcpMIB MODULE-IDENTITY
   LAST-UPDATED "9801290000Z"
   ORGANIZATION "IETF IPv6 MIB Working Group"
   CONTACT-INFO
        "       Mike Daniele

                Postal: Compaq Computer Corporation
                        110 Spitbrook Rd
                        Nashua, NH 03062.
                        US

                Phone:  [phone]
                Email:  [e-mail]"
   DESCRIPTION
        "The MIB module for entities implementing TCP over IPv6."
   ::= { experimental 86 }




Daniele                     Standards Track                     [Page 3]

RFC 2452                    TCP MIB for IPv6               December 1998


-- objects specific to TCP for IPv6

tcp      OBJECT IDENTIFIER ::= { mib-2 6 }

-- the TCP over IPv6 Connection table

-- This connection table contains information about this
-- entity's existing TCP connections between IPv6 endpoints.
-- Only connections between IPv6 addresses are contained in
-- this table.  This entity's connections between IPv4
-- endpoints are contained in tcpConnTable.

ipv6TcpConnTable OBJECT-TYPE
   SYNTAX      SEQUENCE OF Ipv6TcpConnEntry
   MAX-ACCESS  not-accessible
   STATUS      current
   DESCRIPTION
        "A table containing TCP connection-specific information,
         for only those connections whose endpoints are IPv6 addresses."
   ::= { tcp 16 }

ipv6TcpConnEntry OBJECT-TYPE
   SYNTAX      Ipv6TcpConnEntry
   MAX-ACCESS  not-accessible
   STATUS      current
   DESCRIPTION
        "A conceptual row of the ipv6TcpConnTable containing
         information about a particular current TCP connection.
         Each row of this table is transient, in that it ceases to
         exist when (or soon after) the connection makes the transition
         to the CLOSED state.

         Note that conceptual rows in this table require an additional
         index object compared to tcpConnTable, since IPv6 addresses
         are not guaranteed to be unique on the managed node."
   INDEX   { ipv6TcpConnLocalAddress,
             ipv6TcpConnLocalPort,
             ipv6TcpConnRemAddress,
             ipv6TcpConnRemPort,
             ipv6TcpConnIfIndex }
   ::= { ipv6TcpConnTable 1 }

Ipv6TcpConnEntry ::=
   SEQUENCE { ipv6TcpConnLocalAddress    Ipv6Address,
              ipv6TcpConnLocalPort       INTEGER (0..65535),
              ipv6TcpConnRemAddress      Ipv6Address,
              ipv6TcpConnRemPort         INTEGER (0..65535),
              ipv6TcpConnIfIndex         Ipv6IfIndexOrZero,



Daniele                     Standards Track                     [Page 4]

RFC 2452                    TCP MIB for IPv6               December 1998


              ipv6TcpConnState           INTEGER }

ipv6TcpConnLocalAddress OBJECT-TYPE
   SYNTAX     Ipv6Address
   MAX-ACCESS not-accessible
   STATUS     current
   DESCRIPTION
        "The local IPv6 address for this TCP connection. In
         the case of a connection in the listen state which
         is willing to accept connections for any IPv6
         address associated with the managed node, the value
         ::0 is used."
   ::= { ipv6TcpConnEntry 1 }

ipv6TcpConnLocalPort OBJECT-TYPE
   SYNTAX     INTEGER (0..65535)
   MAX-ACCESS not-accessible
   STATUS     current
   DESCRIPTION
        "The local port number for this TCP connection."
   ::= { ipv6TcpConnEntry 2 }

ipv6TcpConnRemAddress OBJECT-TYPE
   SYNTAX     Ipv6Address
   MAX-ACCESS not-accessible
   STATUS     current
   DESCRIPTION
        "The remote IPv6 address for this TCP connection."
   ::= { ipv6TcpConnEntry 3 }

ipv6TcpConnRemPort OBJECT-TYPE
   SYNTAX     INTEGER (0..65535)
   MAX-ACCESS not-accessible
   STATUS     current
   DESCRIPTION
        "The remote port number for this TCP connection."
   ::= { ipv6TcpConnEntry 4 }

ipv6TcpConnIfIndex OBJECT-TYPE
   SYNTAX     Ipv6IfIndexOrZero
   MAX-ACCESS not-accessible
   STATUS     current
   DESCRIPTION
        "An index object used to disambiguate conceptual rows in
         the table, since the connection 4-tuple may not be unique.

         If the connection's remote address (ipv6TcpConnRemAddress)
         is a link-local address and the connection's local address



Daniele                     Standards Track                     [Page 5]