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rfc:rfc2667

Network Working Group D. Thaler Request for Comments: 2667 Microsoft Category: Standards Track August 1999

                           IP Tunnel MIB

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 (1999).  All Rights Reserved.

1. Abstract

 This memo defines a Management Information Base (MIB) for use with
 network management protocols in the Internet community.  In
 particular, it describes managed objects used for managing tunnels of
 any type over IPv4 networks.  Extension MIBs may be designed for
 managing protocol-specific objects. Likewise, extension MIBs may be
 designed for managing security-specific objects.  This MIB does not
 support tunnels over non-IPv4 networks (including IPv6 networks).
 Management of such tunnels may be supported by other MIBs.

Table of Contents

  1 Abstract ...................................................... 1
  2 Introduction .................................................. 2
  3 The SNMP Network Management Framework ......................... 2
  4 Overview ...................................................... 3
  4.1 Relationship to the Interfaces MIB .......................... 3
  4.1.1 Layering Model ............................................ 3
  4.1.2 ifRcvAddressTable ......................................... 4
  4.1.3 ifEntry ................................................... 4
  5 Definitions ................................................... 4
  6 Security Considerations ...................................... 12
  7 Acknowledgements ............................................. 12
  8 Author's Address ............................................. 12
  9 References ................................................... 13
 10 Intellectual Property Notice ................................. 15
 11 Full Copyright Statement ..................................... 16

Thaler Standards Track [Page 1] RFC 2667 IP Tunnel MIB August 1999

2. Introduction

 Over the past several years, there have been a number of "tunneling"
 protocols specified by the IETF (see [28] for an early discussion of
 the model and examples).  This document describes a Management
 Information Base (MIB) used for managing tunnels of any type over
 IPv4 networks, including GRE [16,17], IP-in-IP [18], Minimal
 Encapsulation [19], L2TP [20], PPTP [21], L2F [25], UDP (e.g., [26]),
 ATMP [22], and IPv6-in-IPv4 [27] tunnels.
 Extension MIBs may be designed for managing protocol-specific
 objects.  Likewise, extension MIBs may be designed for managing
 security-specific objects (e.g., IPSEC [24]), and traffic conditioner
 [29] objects.  Finally, this MIB does not support tunnels over non-
 IPv4 networks (including IPv6 networks).  Management of such tunnels
 may be supported by other MIBs.

3. The SNMP Network Management Framework

 The SNMP Management Framework presently consists of five major
 components:
 o    An overall architecture, described in RFC 2571 [1].
 o    Mechanisms for describing and naming objects and events for the
      purpose of management. The first version of this Structure of
      Management Information (SMI) is called SMIv1 and described in
      STD 16, RFC 1155 [2], STD 16, RFC 1212 [3] and RFC 1215 [4]. The
      second version, called SMIv2, is described in STD 58, RFC 2578
      [5], STD 58, RFC 2579 [6] and STD 58, RFC 2580 [7].
 o    Message protocols for transferring management information. The
      first version of the SNMP message protocol is called SNMPv1 and
      described in STD 15, RFC 1157 [8]. A second version of the SNMP
      message protocol, which is not an Internet standards track
      protocol, is called SNMPv2c and described in RFC 1901 [9] and
      RFC 1906 [10].  The third version of the message protocol is
      called SNMPv3 and described in RFC 1906 [10], RFC 2572 [11] and
      RFC 2574 [12].
 o    Protocol operations for accessing management information. The
      first set of protocol operations and associated PDU formats is
      described in STD 15, RFC 1157 [8]. A second set of protocol
      operations and associated PDU formats is described in RFC 1905
      [13].

Thaler Standards Track [Page 2] RFC 2667 IP Tunnel MIB August 1999

 o    A set of fundamental applications described in RFC 2573 [14] and
      the view-based access control mechanism described in RFC 2575
      [15].
 Managed objects are accessed via a virtual information store, termed
 the Management Information Base or MIB.  Objects in the MIB are
 defined using the mechanisms defined in the SMI.
 This memo specifies a MIB module that is compliant to the SMIv2. A
 MIB conforming to the SMIv1 can be produced through the appropriate
 translations. The resulting translated MIB must be semantically
 equivalent, except where objects or events are omitted because no
 translation is possible (use of Counter64). Some machine readable
 information in SMIv2 will be converted into textual descriptions in
 SMIv1 during the translation process. However, this loss of machine
 readable information is not considered to change the semantics of the
 MIB.

4. Overview

 This MIB module contains two tables:
 o    the Tunnel Interface Table, containing information on the
      tunnels known to a router; and
 o    the Tunnel Config Table, which can be used for dynamic creation
      of tunnels, and also provides a mapping from endpoint addresses
      to the current interface index value.

4.1. Relationship to the Interfaces MIB

 This section clarifies the relationship of this MIB to the Interfaces
 MIB [23].  Several areas of correlation are addressed in the
 following subsections.  The implementor is referred to the Interfaces
 MIB document in order to understand the general intent of these
 areas.

4.1.1. Layering Model

 Each logical interface (physical or virtual) has an ifEntry in the
 Interfaces MIB [23].  Tunnels are handled by creating a logical
 interface (ifEntry) for each tunnel. These are then correlated, using
 the ifStack table of the Interfaces MIB, to those interfaces on which
 the local IPv4 addresses of the tunnels are configured.  The basic
 model, therefore, looks something like this (for example):

Thaler Standards Track [Page 3] RFC 2667 IP Tunnel MIB August 1999

       | |         | |          | |
    +--+ +---+  +--+ +---+      | |
    |IP-in-IP|  |  GRE   |      | |
    | tunnel |  | tunnel |      | |
    +--+ +---+  +--+ +---+      | |
       | |         | |          | |    <== attachment to underlying
    +--+ +---------+ +----------+ +--+     interfaces, to be provided
    |       Physical interface       |     by ifStack table
    +--------------------------------+

4.1.2. ifRcvAddressTable

 The ifRcvAddressTable usage is defined in the MIBs defining the
 encapsulation below the network layer.  For example, if IP-in-IP
 encapsulation is being used, the ifRcvAddressTable is defined by IP-
 in-IP.

4.1.3. ifEntry

 IfEntries are defined in the MIBs defining the encapsulation below
 the network layer.  For example, if IP-in-IP encapsulation [20] is
 being used, the ifEntry is defined by IP-in-IP.
 The ifType of a tunnel should be set to "tunnel" (131).  An entry in
 the IP Tunnel MIB will exist for every ifEntry with this ifType.  An
 implementation of the IP Tunnel MIB may allow ifEntries to be created
 via the tunnelConfigTable.  Creating a tunnel will also add an entry
 in the ifTable and in the tunnelIfTable, and deleting a tunnel will
 likewise delete the entry in the ifTable and the tunnelIfTable.
 The use of two different tables in this MIB was an important design
 decision.  Traditionally, ifIndex values are chosen by agents, and
 are permitted to change across restarts.  Allowing row creation
 directly in the Tunnel Interface Table, indexed by ifIndex, would
 complicate row creation and/or cause interoperability problems (if
 each agent had special restrictions on ifIndex). Instead, a separate
 table is used which is indexed only by objects over which the manager
 has control.  Namely, these are the addresses of the tunnel endpoints
 and the encapsulation protocol.  Finally, an additional manager-
 chosen ID is used in the index to support protocols such as L2F which
 allow multiple tunnels between the same endpoints.

Thaler Standards Track [Page 4] RFC 2667 IP Tunnel MIB August 1999

5. Definitions

TUNNEL-MIB DEFINITIONS ::= BEGIN

IMPORTS

  MODULE-IDENTITY, OBJECT-TYPE, transmission,
  Integer32, IpAddress             FROM SNMPv2-SMI
  RowStatus                        FROM SNMPv2-TC
  MODULE-COMPLIANCE, OBJECT-GROUP  FROM SNMPv2-CONF
  ifIndex, InterfaceIndexOrZero    FROM IF-MIB;

tunnelMIB MODULE-IDENTITY

  LAST-UPDATED "9908241200Z" -- August 24, 1999
  ORGANIZATION "IETF Interfaces MIB Working Group"
  CONTACT-INFO
          " Dave Thaler
            Microsoft Corporation
            One Microsoft Way
            Redmond, WA  98052-6399
            EMail: dthaler@dthaler.microsoft.com"
  DESCRIPTION
          "The MIB module for management of IP Tunnels, independent of
          the specific encapsulation scheme in use."
  REVISION     "9908241200Z" -- August 24, 1999
  DESCRIPTION
          "Initial version, published as RFC 2667."
  ::= { transmission 131 }

tunnelMIBObjects OBJECT IDENTIFIER ::= { tunnelMIB 1 }

tunnel OBJECT IDENTIFIER ::= { tunnelMIBObjects 1 }

– the IP Tunnel MIB-Group – – a collection of objects providing information about – IP Tunnels

tunnelIfTable OBJECT-TYPE

  SYNTAX     SEQUENCE OF TunnelIfEntry
  MAX-ACCESS not-accessible
  STATUS     current
  DESCRIPTION
          "The (conceptual) table containing information on configured
          tunnels."
  ::= { tunnel 1 }

tunnelIfEntry OBJECT-TYPE

  SYNTAX     TunnelIfEntry

Thaler Standards Track [Page 5] RFC 2667 IP Tunnel MIB August 1999

  MAX-ACCESS not-accessible
  STATUS     current
  DESCRIPTION
          "An entry (conceptual row) containing the information on a
          particular configured tunnel."
  INDEX      { ifIndex }
  ::= { tunnelIfTable 1 }

TunnelIfEntry ::= SEQUENCE {

  tunnelIfLocalAddress            IpAddress,
  tunnelIfRemoteAddress           IpAddress,
  tunnelIfEncapsMethod            INTEGER,
  tunnelIfHopLimit                Integer32,
  tunnelIfSecurity                INTEGER,
  tunnelIfTOS                     Integer32

}

tunnelIfLocalAddress OBJECT-TYPE

  SYNTAX     IpAddress
  MAX-ACCESS read-only
  STATUS     current
  DESCRIPTION
          "The address of the local endpoint of the tunnel (i.e., the
          source address used in the outer IP header), or 0.0.0.0 if
          unknown."
  ::= { tunnelIfEntry 1 }

tunnelIfRemoteAddress OBJECT-TYPE

  SYNTAX     IpAddress
  MAX-ACCESS read-only
  STATUS     current
  DESCRIPTION
          "The address of the remote endpoint of the tunnel (i.e., the
          destination address used in the outer IP header), or 0.0.0.0
          if unknown."
  ::= { tunnelIfEntry 2 }

tunnelIfEncapsMethod OBJECT-TYPE

  SYNTAX     INTEGER {
                 other(1),   -- none of the following
                 direct(2),  -- no intermediate header
                 gre(3),     -- GRE encapsulation
                 minimal(4), -- Minimal encapsulation
                 l2tp(5),    -- L2TP encapsulation
                 pptp(6),    -- PPTP encapsulation
                 l2f(7),     -- L2F encapsulation
                 udp(8),     -- UDP encapsulation
                 atmp(9)     -- ATMP encapsulation

Thaler Standards Track [Page 6] RFC 2667 IP Tunnel MIB August 1999

             }
  MAX-ACCESS read-only
  STATUS     current
  DESCRIPTION
          "The encapsulation method used by the tunnel. The value
          direct indicates that the packet is encapsulated directly
          within a normal IPv4 header, with no intermediate header,
          and unicast to the remote tunnel endpoint (e.g., an RFC 2003
          IP-in-IP tunnel, or an RFC 1933 IPv6-in-IPv4 tunnel). The
          value minimal indicates that a Minimal Forwarding Header
          (RFC 2004) is inserted between the outer header and the
          payload packet. The value UDP indicates that the payload
          packet is encapsulated within a normal UDP packet (e.g., RFC
          1234).  The remaining protocol-specific values indicate that
          a header of the protocol of that name is inserted between
          the outer header and the payload header."
  ::= { tunnelIfEntry 3 }

tunnelIfHopLimit OBJECT-TYPE

  SYNTAX     Integer32 (0..255)
  MAX-ACCESS read-write
  STATUS     current
  DESCRIPTION
          "The TTL to use in the outer IP header. A value of 0
          indicates that the value is copied from the payload's
          header."
  ::= { tunnelIfEntry 4 }

tunnelIfSecurity OBJECT-TYPE

  SYNTAX     INTEGER {
                 none(1),   -- no security
                 ipsec(2),  -- IPSEC security
                 other(3)
             }
  MAX-ACCESS read-only
  STATUS     current
  DESCRIPTION
          "The method used by the tunnel to secure the outer IP
          header.  The value ipsec indicates that IPsec is used
          between the tunnel endpoints for authentication or
          encryption or both.  More specific security-related
          information may be available in a MIB for the security
          protocol in use."
  ::= { tunnelIfEntry 5 }

tunnelIfTOS OBJECT-TYPE

  SYNTAX     Integer32 (-2..63)
  MAX-ACCESS read-write

Thaler Standards Track [Page 7] RFC 2667 IP Tunnel MIB August 1999

  STATUS     current
  DESCRIPTION
          "The method used to set the high 6 bits of the TOS in the
          outer IP header.  A value of -1 indicates that the bits are
          copied from the payload's header. A value of -2 indicates
          that a traffic conditioner is invoked and more information
          may be available in a traffic conditioner MIB.  A value
          between 0 and 63 inclusive indicates that the bit field is
          set to the indicated value."
  ::= { tunnelIfEntry 6 }

tunnelConfigTable OBJECT-TYPE

  SYNTAX     SEQUENCE OF TunnelConfigEntry
  MAX-ACCESS not-accessible
  STATUS     current
  DESCRIPTION
          "The (conceptual) table containing information on configured
          tunnels.  This table can be used to map a set of tunnel
          endpoints to the associated ifIndex value.  It can also be
          used for row creation.  Note that every row in the
          tunnelIfTable with a fixed destination address should have a
          corresponding row in the tunnelConfigTable, regardless of
          whether it was created via SNMP."
  ::= { tunnel 2 }

tunnelConfigEntry OBJECT-TYPE

  SYNTAX     TunnelConfigEntry
  MAX-ACCESS not-accessible
  STATUS     current
  DESCRIPTION
          "An entry (conceptual row) containing the information on a
          particular configured tunnel."
  INDEX      { tunnelConfigLocalAddress,
               tunnelConfigRemoteAddress,
               tunnelConfigEncapsMethod,
               tunnelConfigID }
  ::= { tunnelConfigTable 1 }

TunnelConfigEntry ::= SEQUENCE {

  tunnelConfigLocalAddress            IpAddress,
  tunnelConfigRemoteAddress           IpAddress,
  tunnelConfigEncapsMethod            INTEGER,
  tunnelConfigID                      Integer32,
  tunnelConfigIfIndex                 InterfaceIndexOrZero,
  tunnelConfigStatus                  RowStatus

}

tunnelConfigLocalAddress OBJECT-TYPE

Thaler Standards Track [Page 8] RFC 2667 IP Tunnel MIB August 1999

  SYNTAX     IpAddress
  MAX-ACCESS not-accessible
  STATUS     current
  DESCRIPTION
          "The address of the local endpoint of the tunnel, or 0.0.0.0
          if the device is free to choose any of its addresses at
          tunnel establishment time."
  ::= { tunnelConfigEntry 1 }

tunnelConfigRemoteAddress OBJECT-TYPE

  SYNTAX     IpAddress
  MAX-ACCESS not-accessible
  STATUS     current
  DESCRIPTION
          "The address of the remote endpoint of the tunnel."
  ::= { tunnelConfigEntry 2 }

tunnelConfigEncapsMethod OBJECT-TYPE

  SYNTAX     INTEGER {
                 other(1),   -- none of the following
                 direct(2),  -- no intermediate header
                 gre(3),     -- GRE encapsulation
                 minimal(4), -- Minimal encapsulation
                 l2tp(5),    -- L2TP encapsulation
                 pptp(6),    -- PPTP encapsulation
                 l2f(7),     -- L2F encapsulation
                 udp(8),     -- UDP encapsulation
                 atmp(9)
             }
  MAX-ACCESS not-accessible
  STATUS     current
  DESCRIPTION
          "The encapsulation method used by the tunnel."
  ::= { tunnelConfigEntry 3 }

tunnelConfigID OBJECT-TYPE

  SYNTAX     Integer32 (1..2147483647)
  MAX-ACCESS not-accessible
  STATUS     current
  DESCRIPTION
          "An identifier used to distinguish between multiple tunnels
          of the same encapsulation method, with the same endpoints.
          If the encapsulation protocol only allows one tunnel per set
          of endpoint addresses (such as for GRE or IP-in-IP), the
          value of this object is 1.  For encapsulation methods (such
          as L2F) which allow multiple parallel tunnels, the manager
          is responsible for choosing any ID which does not conflict
          with an existing row, such as choosing a random number."

Thaler Standards Track [Page 9] RFC 2667 IP Tunnel MIB August 1999

  ::= { tunnelConfigEntry 4 }

tunnelConfigIfIndex OBJECT-TYPE

  SYNTAX     InterfaceIndexOrZero
  MAX-ACCESS read-only
  STATUS     current
  DESCRIPTION
          "If the value of tunnelConfigStatus for this row is active,
          then this object contains the value of ifIndex corresponding
          to the tunnel interface.  A value of 0 is not legal in the
          active state, and means that the interface index has not yet
          been assigned."
  ::= { tunnelConfigEntry 5 }

tunnelConfigStatus OBJECT-TYPE

  SYNTAX     RowStatus
  MAX-ACCESS read-create
  STATUS     current
  DESCRIPTION
          "The status of this row, by which new entries may be
          created, or old entries deleted from this table. The agent
          need not support setting this object to createAndWait or
          notInService since there are no other writable objects in
          this table, and writable objects in rows of corresponding
          tables such as the tunnelIfTable may be modified while this
          row is active.
          To create a row in this table for an encapsulation method
          which does not support multiple parallel tunnels with the
          same endpoints, the management station should simply use a
          tunnelConfigID of 1, and set tunnelConfigStatus to
          createAndGo.  For encapsulation methods such as L2F which
          allow multiple parallel tunnels, the management station may
          select a pseudo-random number to use as the tunnelConfigID
          and set tunnelConfigStatus to createAndGo.  In the event
          that this ID is already in use and an inconsistentValue is
          returned in response to the set operation, the management
          station should simply select a new pseudo-random number and
          retry the operation.
          Creating a row in this table will cause an interface index
          to be assigned by the agent in an implementation-dependent
          manner, and corresponding rows will be instantiated in the
          ifTable and the tunnelIfTable.  The status of this row will
          become active as soon as the agent assigns the interface
          index, regardless of whether the interface is operationally
          up.

Thaler Standards Track [Page 10] RFC 2667 IP Tunnel MIB August 1999

          Deleting a row in this table will likewise delete the
          corresponding row in the ifTable and in the tunnelIfTable."
  ::= { tunnelConfigEntry 6 }

– conformance information

tunnelMIBConformance

                OBJECT IDENTIFIER ::= { tunnelMIB 2 }

tunnelMIBCompliances

                OBJECT IDENTIFIER ::= { tunnelMIBConformance 1 }

tunnelMIBGroups OBJECT IDENTIFIER ::= { tunnelMIBConformance 2 }

– compliance statements

tunnelMIBCompliance MODULE-COMPLIANCE

  STATUS  current
  DESCRIPTION
          "The compliance statement for the IP Tunnel MIB."
  MODULE  -- this module
  MANDATORY-GROUPS { tunnelMIBBasicGroup }
      OBJECT      tunnelIfHopLimit
      MIN-ACCESS  read-only
      DESCRIPTION
          "Write access is not required."
      OBJECT      tunnelIfTOS
      MIN-ACCESS  read-only
      DESCRIPTION
          "Write access is not required."
      OBJECT      tunnelConfigStatus
      MIN-ACCESS  read-only
      DESCRIPTION
          "Write access is not required."
 ::= { tunnelMIBCompliances 1 }

– units of conformance

tunnelMIBBasicGroup OBJECT-GROUP

  OBJECTS { tunnelIfLocalAddress, tunnelIfRemoteAddress,
     tunnelIfEncapsMethod, tunnelIfHopLimit, tunnelIfTOS,
     tunnelIfSecurity, tunnelConfigIfIndex, tunnelConfigStatus }
  STATUS  current
  DESCRIPTION
          "A collection of objects to support basic management of IP
          Tunnels."
  ::= { tunnelMIBGroups 1 }

Thaler Standards Track [Page 11] RFC 2667 IP Tunnel MIB August 1999

END

6. Security Considerations

 This MIB contains readable objects whose values provide information
 related to IP tunnel interfaces.  There are also a number of objects
 that have a MAX-ACCESS clause of read-write and/or read-create, such
 as those which allow an administrator to dynamically configure
 tunnels.
 While unauthorized access to the readable objects is relatively
 innocuous, unauthorized access to the write-able objects could cause
 a denial of service, or could cause unauthorized creation and/or
 manipulation of tunnels. Hence, the support for SET operations in a
 non-secure environment without proper protection can have a negative
 effect on network operations.
 SNMPv1 by itself is such an insecure environment.  Even if the
 network itself is secure (for example by using IPSec [24]), even
 then, there is no control as to who on the secure network is allowed
 to access and SET (change/create/delete) the objects in this MIB.
 It is recommended that the implementers consider the security
 features as provided by the SNMPv3 framework.  Specifically, the use
 of the User-based Security Model RFC 2574 [12] and the View-based
 Access Control Model RFC 2575 [15] is recommended.
 It is then a customer/user responsibility to ensure that the SNMP
 entity giving access to this MIB, is properly configured to give
 access to those objects only to those principals (users) that have
 legitimate rights to access them.

7. Acknowledgements

 This MIB module was updated based on feedback from the IETF's
 Interfaces MIB (IF-MIB) and Point-to-Point Protocol Extensions
 (PPPEXT) Working Groups.

8. Author's Address

 Dave Thaler
 Microsoft Corporation
 One Microsoft Way
 Redmond, WA  98052-6399
 Phone: +1 425 703 8835
 EMail: dthaler@microsoft.com

Thaler Standards Track [Page 12] RFC 2667 IP Tunnel MIB August 1999

9. References

 [1]  Wijnen, B., Harrington, D. and R. Presuhn, "An Architecture for
      Describing SNMP Management Frameworks", RFC 2571, April 1999.
 [2]  Rose, M. and K. McCloghrie, "Structure and Identification of
      Management Information for TCP/IP-based Internets", STD 16, RFC
      1155, May 1990.
 [3]  Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD 16,
      RFC 1212, March 1991.
 [4]  Rose, M., "A Convention for Defining Traps for use with the
      SNMP", RFC 1215, March 1991.
 [5]  McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Structure of
      Management Information Version 2 (SMIv2)", STD 58, RFC 2578,
      April 1999.
 [6]  McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Textual
      Conventions for SMIv2", STD 58, RFC 2579, April 1999.
 [7]  McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Conformance
      Statements for SMIv2", STD 58, RFC 2580, April 1999.
 [8]  Case, J., Fedor, M., Schoffstall, M. and J. Davin, "Simple
      Network Management Protocol", STD 15, RFC 1157, May 1990.
 [9]  Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
      "Introduction to Community-based SNMPv2", RFC 1901, January
      1996.
 [10] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Transport
      Mappings for Version 2 of the Simple Network Management Protocol
      (SNMPv2)", RFC 1906, January 1996.
 [11] Case, J., Harrington D., Presuhn R. and B. Wijnen, "Message
      Processing and Dispatching for the Simple Network Management
      Protocol (SNMP)", RFC 2572, April 1999.
 [12] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM)
      for version 3 of the Simple Network Management Protocol
      (SNMPv3)", RFC 2574, April 1999.
 [13] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Protocol
      Operations for Version 2 of the Simple Network Management
      Protocol (SNMPv2)", RFC 1905, January 1996.

Thaler Standards Track [Page 13] RFC 2667 IP Tunnel MIB August 1999

 [14] Levi, D., Meyer, P. and B. Stewart, "SNMPv3 Applications", RFC
      2573, April 1999.
 [15] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access
      Control Model (VACM) for the Simple Network Management Protocol
      (SNMP)", RFC 2575, April 1999.
 [16] Hanks, S., Li, T., Farinacci, D. and P. Traina, "Generic Routing
      Encapsulation (GRE)", RFC 1701, October 1994.
 [17] Hanks, S., Li, T., Farinacci, D. and P. Traina, "Generic Routing
      Encapsulation over IPv4 networks", RFC 1702, October 1994.
 [18] Perkins, C., "IP Encapsulation within IP", RFC 2003, October
      1996.
 [19] Perkins, C., "Minimal Encapsulation within IP", RFC 2004,
      October 1996.
 [20] Townsley, W., Valencia, A., Rubens, A., Pall, G., Zorn, G. and
      B. Palter, "Layer Two Tunneling Protocol "L2TP"", RFC 2661,
      August 1999.
 [21] Hamzeh, K., Pall, G., Verthein, W. Taarud, J., Little, W. and G.
      Zorn, "Point-to-Point Tunneling Protocol", RFC 2637, July 1999.
 [22] Hamzeh, K., "Ascend Tunnel Management Protocol - ATMP", RFC
      2107, February 1997.
 [23] McCloghrie, K. and F. Kastenholz.  "The Interfaces Group MIB
      using SMIv2", RFC 2233, November 1997.
 [24] R. Atkinson,  "Security architecture for the internet protocol",
      RFC 2401, November 1998.
 [25] Valencia, A., Littlewood, M. and T. Kolar.  "Cisco Layer Two
      Forwarding (Protocol) "L2F"", RFC 2341, May 1998.
 [26] D. Provan,  "Tunneling IPX Traffic through IP Networks", RFC
      1234, June 1991.
 [27] Gilligan, R. and E. Nordmark.  "Transition Mechanisms for IPv6
      Hosts and Routers", RFC 1933, April 1996.
 [28] Woodburn, R. and D. Mills, "A Scheme for an Internet
      Encapsulation Protocol: Version 1", RFC 1241, July 1991.

Thaler Standards Track [Page 14] RFC 2667 IP Tunnel MIB August 1999

 [29] 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.

10. Intellectual Property Notice

 The IETF takes no position regarding the validity or scope of any
 intellectual property 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; neither does it represent that it
 has made any effort to identify any such rights.  Information on the
 IETF's procedures with respect to rights in standards-track and
 standards-related documentation can be found in BCP-11.  Copies of
 claims of rights made available for publication 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 Secretariat."
 The IETF invites any interested party to bring to its attention any
 copyrights, patents or patent applications, or other proprietary
 rights which may cover technology that may be required to practice
 this standard.  Please address the information to the IETF Executive
 Director.

Thaler Standards Track [Page 15] RFC 2667 IP Tunnel MIB August 1999

11. Full Copyright Statement

 Copyright (C) The Internet Society (1999).  All Rights Reserved.
 This document and translations of it may be copied and furnished to
 others, and derivative works that comment on or otherwise explain it
 or assist in its implementation may be prepared, copied, published
 and distributed, in whole or in part, without restriction of any
 kind, provided that the above copyright notice and this paragraph are
 included on all such copies and derivative works.  However, this
 document itself may not be modified in any way, such as by removing
 the copyright notice or references to the Internet Society or other
 Internet organizations, except as needed for the purpose of
 developing Internet standards in which case the procedures for
 copyrights defined in the Internet Standards process must be
 followed, or as required to translate it into languages other than
 English.
 The limited permissions granted above are perpetual and will not be
 revoked by the Internet Society or its successors or assigns.
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Thaler Standards Track [Page 16]

/data/webs/external/dokuwiki/data/pages/rfc/rfc2667.txt · Last modified: 1999/08/26 18:58 (external edit)