path: root/doc/rfc/rfc7856.txt

Internet Engineering Task Force (IETF)                            Y. Cui
Request for Comments: 7856                                       J. Dong
Category: Standards Track                                          P. Wu
ISSN: 2070-1721                                                    M. Xu
                                                     Tsinghua University
                                                           A. Yla-Jaaski
                                                        Aalto University
                                                                May 2016


            Softwire Mesh Management Information Base (MIB)

Abstract

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in the Internet community.
   In particular, it defines objects for managing a softwire mesh.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc7856.

Copyright Notice

   Copyright (c) 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.





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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  The Internet-Standard Management Framework  . . . . . . . . .   2
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Structure of the MIB Module . . . . . . . . . . . . . . . . .   3
     4.1.  The swmSupportedTunnelTable Subtree . . . . . . . . . . .   3
     4.2.  The swmEncapsTable Subtree  . . . . . . . . . . . . . . .   3
     4.3.  The swmBGPNeighborTable Subtree . . . . . . . . . . . . .   4
     4.4.  The swmConformance Subtree  . . . . . . . . . . . . . . .   4
   5.  Relationship to Other MIB Modules . . . . . . . . . . . . . .   4
     5.1.  Relationship to the IF-MIB  . . . . . . . . . . . . . . .   4
     5.2.  Relationship to the IP Tunnel MIB . . . . . . . . . . . .   5
     5.3.  MIB Modules Required for IMPORTS  . . . . . . . . . . . .   5
   6.  Definitions . . . . . . . . . . . . . . . . . . . . . . . . .   6
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  13
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  15
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  15
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  16
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  17
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  17

1.  Introduction

   The softwire mesh framework [RFC5565] is a tunneling mechanism that
   enables connectivity between islands of IPv4 networks across a single
   IPv6 backbone and vice versa.  In a softwire mesh, extended
   Multiprotocol BGP (MP-BGP) is used to set up tunnels and advertise
   prefixes among Address Family Border Routers (AFBRs).

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in the Internet community.
   In particular, it defines objects for managing a softwire mesh
   [RFC5565].

2.  The Internet-Standard Management Framework

   For a detailed overview of the documents that describe the current
   Internet-Standard Management Framework, please refer to section 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




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   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].

3.  Terminology

   This document uses terminology from the softwire problem statement
   [RFC4925], the BGP encapsulation Subsequent Address Family Identifier
   (SAFI), the BGP tunnel encapsulation attribute [RFC5512], the
   softwire mesh framework [RFC5565], and the BGP IPsec tunnel
   encapsulation attribute [RFC5566].

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in RFC
   2119 [RFC2119].

4.  Structure of the MIB Module

   The Softwire Mesh MIB provides a method to monitor the softwire mesh
   objects through SNMP.

4.1.  The swmSupportedTunnelTable Subtree

   The swmSupportedTunnelTable subtree provides the information about
   what types of tunnels can be used for softwire mesh scenarios in the
   AFBR.  The softwire mesh framework [RFC5565] does not mandate the use
   of any particular tunneling technology.  Based on the BGP tunnel
   encapsulation attribute tunnel types introduced by RFC 5512 [RFC5512]
   and RFC 5566 [RFC5566], the softwire mesh tunnel types include at
   least L2TPv3 (Layer 2 Tunneling Protocol version 3) over IP, GRE
   (Generic Routing Encapsulation), Transmit tunnel endpoint, IPsec in
   Tunnel-mode, IP in IP tunnel with IPsec Transport Mode, MPLS-in-IP
   tunnel with IPsec Transport Mode, and IP in IP.  The detailed
   encapsulation information of different tunnel types (e.g., L2TPv3
   Session ID, GRE Key, etc.) is not managed in the Softwire Mesh MIB.

4.2.  The swmEncapsTable Subtree

   The swmEncapsTable subtree provides softwire mesh NLRI-NH information
   (Network Layer Reachability Information - Next Hop) about the AFBR.
   It keeps the mapping between the External-IP (E-IP) prefix and the
   Internal-IP (I-IP) address of the next hop.  The mappings determine
   which I-IP destination address will be used to encapsulate the
   received packet according to its E-IP destination address.  The
   definitions of E-IP and I-IP are explained in Section 4.1 of RFC 5565
   [RFC5565].  The number of entries in swmEncapsTable shows how many
   softwire mesh tunnels are maintained in this AFBR.



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4.3.  The swmBGPNeighborTable Subtree

   This subtree provides the softwire mesh BGP neighbor information of
   an AFBR.  It includes the address of the softwire mesh BGP peer and
   the kind of tunnel that the AFBR would use to communicate with this
   BGP peer.

4.4.  The swmConformance Subtree

   This subtree provides the conformance information of MIB objects.

5.  Relationship to Other MIB Modules

5.1.  Relationship to the IF-MIB

   The Interfaces MIB [RFC2863] defines generic managed objects for
   managing interfaces.  Each logical interface (physical or virtual)
   has an ifEntry.  Tunnels are handled by creating logical interfaces
   (ifEntry).  Being a tunnel, the softwire mesh interface has an entry
   in the Interface MIB, as well as an entry in the IP Tunnel MIB.
   Those corresponding entries are indexed by ifIndex.

   The ifOperStatus in the ifTable represents whether the mesh function
   of the AFBR has been triggered.  If the softwire mesh capability is
   negotiated during the BGP OPEN phase, the mesh function is considered
   to be started, and the ifOperStatus is "up".  Otherwise, the
   ifOperStatus is "down".

   In the case of an IPv4-over-IPv6 softwire mesh tunnel, ifInUcastPkts
   counts the number of IPv6 packets that are sent to the virtual
   interface for decapsulation into IPv4.  The ifOutUcastPkts counts the
   number of IPv6 packets that are generated by encapsulating IPv4
   packets sent to the virtual interface.  In particular, if these IPv4
   packets need fragmentation, ifOutUcastPkts counts the number of
   packets after fragmentation.

   In the case of an IPv6-over-IPv4 softwire mesh tunnel, ifInUcastPkts
   counts the number of IPv4 packets that are delivered to the virtual
   interface for decapsulation into IPv6.  The ifOutUcastPkts counts the
   number of IPv4 packets that are generated by encapsulating IPv6
   packets sent down to the virtual interface.  In particular, if these
   IPv6 packets need to be fragmented, ifOutUcastPkts counts the number
   of packets after fragmentation.  Similar definitions apply to other
   counter objects in the ifTable.







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5.2.  Relationship to the IP Tunnel MIB

   The IP Tunnel MIB [RFC4087] contains objects applicable to all IP
   tunnels, including softwire mesh tunnels.  Meanwhile, the Softwire
   Mesh MIB extends the IP Tunnel MIB to further describe encapsulation-
   specific information.

   When running a point-to-multipoint tunnel, it is necessary for a
   softwire mesh AFBR to maintain an encapsulation table in order to
   perform correct "forwarding" among AFBRs.  This forwarding function
   on an AFBR is performed by using the E-IP destination address to look
   up the I-IP encapsulation destination address in the encapsulation
   table.  An AFBR also needs to know the BGP peer information of the
   other AFBRs, so that it can negotiate the NLRI-NH information and the
   tunnel parameters with them.

   The Softwire Mesh MIB requires the implementation of the IP Tunnel
   MIB.  The tunnelIfEncapsMethod in the tunnelIfEntry MUST be set to
   softwireMesh(16), and a corresponding entry in the Softwire Mesh MIB
   module will be presented for the tunnelIfEntry.  The
   tunnelIfRemoteInetAddress MUST be set to "0.0.0.0" for IPv4 or "::"
   for IPv6 because it is a point-to-multipoint tunnel.

   The tunnelIfAddressType in the tunnelIfTable represents the type of
   address in the corresponding tunnelIfLocalInetAddress and
   tunnelIfRemoteInetAddress objects.  The tunnelIfAddressType is
   identical to swmEncapsIIPDstType in softwire mesh, which can support
   either IPv4-over-IPv6 or IPv6-over-IPv4.  When the
   swmEncapsEIPDstType is IPv6 and the swmEncapsIIPDstType is IPv4, the
   tunnel type is IPv6-over-IPv4; when the swmEncapsEIPDstType is IPv4
   and the swmEncapsIIPDstType is IPv6, the encapsulation mode is IPv4-
   over-IPv6.

5.3.  MIB Modules Required for IMPORTS

   The following MIB module IMPORTS objects from SNMPv2-SMI [RFC2578],
   SNMPv2-CONF [RFC2580], IF-MIB [RFC2863], and INET-ADDRESS-MIB
   [RFC4001].













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6.  Definitions

   SOFTWIRE-MESH-MIB DEFINITIONS ::= BEGIN

   IMPORTS
       MODULE-IDENTITY, OBJECT-TYPE, mib-2 FROM SNMPv2-SMI

       OBJECT-GROUP, MODULE-COMPLIANCE             FROM SNMPv2-CONF

       InetAddress, InetAddressType, InetAddressPrefixLength

       FROM INET-ADDRESS-MIB

       ifIndex                                FROM IF-MIB

       IANAtunnelType                         FROM IANAifType-MIB;

       swmMIB MODULE-IDENTITY
       LAST-UPDATED "201605110000Z"        -- May 11, 2016
       ORGANIZATION "Softwire Working Group"
       CONTACT-INFO
                "Yong Cui
                 Email:  yong@csnet1.cs.tsinghua.edu.cn

                 Jiang Dong
                 Email:  knight.dongjiang@gmail.com

                 Peng Wu
                 Email:  weapon9@gmail.com

                 Mingwei Xu
                 Email:  xmw@cernet.edu.cn

                 Antti Yla-Jaaski
                 Email:  antti.yla-jaaski@aalto.fi

                 Email comments directly to the Softwire WG Mailing
                 List at softwires@ietf.org
                "
       DESCRIPTION
              "This MIB module contains managed object definitions for
               the softwire mesh framework.

               Copyright (c) 2016 IETF Trust and the persons
               identified as authors of the code.  All rights reserved.

               Redistribution and use in source and binary forms, with
               or without modification, is permitted pursuant to, and



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               subject to the license terms contained in, the Simplified
               BSD License set forth in Section 4.c of the IETF Trust's
               Legal Provisions Relating to IETF Documents
               (http://trustee.ietf.org/license-info)."
       REVISION    "201605110000Z"
       DESCRIPTION "Initial version, published as RFC 7856"
       ::= { mib-2 239 }

   swmObjects OBJECT IDENTIFIER ::= { swmMIB 1 }

   -- swmSupportedTunnelTable
   swmSupportedTunnelTable OBJECT-TYPE
       SYNTAX      SEQUENCE OF SwmSupportedTunnelEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A table of objects that show what kinds of tunnels
           can be supported by the AFBR."
       ::= { swmObjects 1 }

   swmSupportedTunnelEntry  OBJECT-TYPE
       SYNTAX      SwmSupportedTunnelEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A set of objects that show what kinds of tunnels
           can be supported in the AFBR.  If the AFBR supports
           multiple tunnel types, the swmSupportedTunnelTable
           would have several entries."
       INDEX { swmSupportedTunnelType }
       ::= { swmSupportedTunnelTable 1 }

   SwmSupportedTunnelEntry ::= SEQUENCE {
       swmSupportedTunnelType              IANAtunnelType
   }

   swmSupportedTunnelType OBJECT-TYPE
       SYNTAX      IANAtunnelType
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "Represents the tunnel type that can be used for softwire
           mesh scenarios, such as L2TPv3 over IP, GRE, Transmit
           tunnel endpoint, IPsec in Tunnel-mode, IP in IP tunnel with
           IPsec Transport Mode, MPLS-in-IP tunnel with IPsec Transport
           Mode, and IP in IP.  There is no restriction on the tunnel
           type the softwire mesh can use."
        REFERENCE



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           "L2TPv3 over IP, GRE, and IP in IP in RFC 5512.
           Transmit tunnel endpoint, IPsec in Tunnel-mode, IP in IP
           tunnel with IPsec Transport Mode, MPLS-in-IP tunnel with
           IPsec Transport Mode in RFC 5566."
       ::= { swmSupportedTunnelEntry 1 }

   -- end of swmSupportedTunnelTable

   --swmEncapsTable
   swmEncapsTable OBJECT-TYPE
       SYNTAX      SEQUENCE OF SwmEncapsEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A table of objects that display the
           softwire mesh encapsulation information."
       ::= { swmObjects 2 }

   swmEncapsEntry  OBJECT-TYPE
       SYNTAX      SwmEncapsEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A table of objects that manage the softwire mesh I-IP
            encapsulation destination based on the E-IP destination
            prefix."
       INDEX { ifIndex,
               swmEncapsEIPDstType,
               swmEncapsEIPDst,
               swmEncapsEIPPrefixLength
             }
       ::= { swmEncapsTable 1 }

   SwmEncapsEntry ::=      SEQUENCE {
       swmEncapsEIPDstType       InetAddressType,
       swmEncapsEIPDst           InetAddress,
       swmEncapsEIPPrefixLength  InetAddressPrefixLength,
       swmEncapsIIPDstType       InetAddressType,
       swmEncapsIIPDst           InetAddress
   }

   swmEncapsEIPDstType OBJECT-TYPE
       SYNTAX      InetAddressType
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "This object specifies the address type used for
           swmEncapsEIPDst.  It is different from the



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           tunnelIfAddressType in the tunnelIfTable.  The
           swmEncapsEIPDstType is IPv6 (2) if it is IPv6-over-IPv4
           tunneling.  The swmEncapsEIPDstType is
           IPv4 (1) if it is IPv4-over-IPv6 tunneling."
       REFERENCE
           "IPv4 and IPv6 in RFC 4001."
       ::= { swmEncapsEntry 1 }

   swmEncapsEIPDst OBJECT-TYPE
       SYNTAX      InetAddress
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "The E-IP destination prefix, which is
           used for I-IP encapsulation destination looking up.
           The type of this address is determined by the
           value of swmEncapsEIPDstType"
       REFERENCE
           "E-IP and I-IP in RFC 5565."
       ::= { swmEncapsEntry 2 }

   swmEncapsEIPPrefixLength OBJECT-TYPE
       SYNTAX      InetAddressPrefixLength
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "The prefix length of the E-IP destination prefix."
       ::= { swmEncapsEntry 3 }

   swmEncapsIIPDstType OBJECT-TYPE
       SYNTAX      InetAddressType
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "This object specifies the address type used for
            swmEncapsIIPDst.  It is the same as the tunnelIfAddressType
            in the tunnelIfTable."
       REFERENCE
           "IPv4 and IPv6 in RFC 4001."
       ::= { swmEncapsEntry 4 }

   swmEncapsIIPDst OBJECT-TYPE
       SYNTAX      InetAddress
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "The I-IP destination address, which is used as the
           encapsulation destination for the corresponding E-IP



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           prefix.  Since the tunnelIfRemoteInetAddress in the
           tunnelIfTable should be 0.0.0.0 or ::, swmEncapIIPDst
           should be the destination address used in the outer
           IP header."
       REFERENCE
           "E-IP and I-IP in RFC 5565."
       ::= { swmEncapsEntry 5 }
   -- End of swmEncapsTable

   -- swmBGPNeighborTable
   swmBGPNeighborTable OBJECT-TYPE
       SYNTAX      SEQUENCE OF SwmBGPNeighborEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A table of objects that display the softwire mesh
           BGP neighbor information."
       ::= { swmObjects 3 }

   swmBGPNeighborEntry  OBJECT-TYPE
       SYNTAX      SwmBGPNeighborEntry
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "A set of objects that display the softwire mesh
           BGP neighbor information."
       INDEX {
               ifIndex,
               swmBGPNeighborInetAddressType,
               swmBGPNeighborInetAddress
             }
       ::= { swmBGPNeighborTable 1 }

   SwmBGPNeighborEntry ::= SEQUENCE {
           swmBGPNeighborInetAddressType    InetAddressType,
           swmBGPNeighborInetAddress        InetAddress,
           swmBGPNeighborTunnelType         IANAtunnelType
   }

   swmBGPNeighborInetAddressType OBJECT-TYPE
       SYNTAX      InetAddressType
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "This object specifies the address type used for
            swmBGPNeighborInetAddress."
       ::= { swmBGPNeighborEntry 1 }




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   swmBGPNeighborInetAddress OBJECT-TYPE
       SYNTAX      InetAddress
       MAX-ACCESS  not-accessible
       STATUS      current
       DESCRIPTION
           "The address of the AFBR's BGP neighbor.  The
           address type is the same as the tunnelIfAddressType
           in the tunnelIfTable."
       ::= { swmBGPNeighborEntry 2 }

   swmBGPNeighborTunnelType OBJECT-TYPE
       SYNTAX      IANAtunnelType
       MAX-ACCESS  read-only
       STATUS      current
       DESCRIPTION
           "Represents the type of tunnel that the AFBR
           chooses to transmit traffic with another AFBR/BGP
           neighbor."
       ::= { swmBGPNeighborEntry 3 }
   -- End of swmBGPNeighborTable


   -- conformance information
   swmConformance
                       OBJECT IDENTIFIER ::= { swmMIB 2 }
   swmCompliances
                       OBJECT IDENTIFIER ::= { swmConformance 1 }
   swmGroups
                       OBJECT IDENTIFIER ::= { swmConformance 2 }

    -- compliance statements
   swmCompliance MODULE-COMPLIANCE
      STATUS current
      DESCRIPTION
          "Describes the requirements for conformance to the Softwire
          Mesh MIB.

          The following index objects cannot be added as OBJECT
          clauses but nevertheless have compliance requirements:
          "
          -- OBJECT  swmEncapsEIPDstType
          -- SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
          -- DESCRIPTION
          -- "An implementation is required to support
          --  global IPv4 and/or IPv6 addresses, depending
          --  on its support for IPv4 and IPv6."

          -- OBJECT  swmEncapsEIPDst



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          -- SYNTAX  InetAddress (SIZE(4|16))
          -- DESCRIPTION
          -- "An implementation is required to support
          --  global IPv4 and/or IPv6 addresses, depending
          --  on its support for IPv4 and IPv6."

          -- OBJECT  swmEncapsEIPPrefixLength
          -- SYNTAX  InetAddressPrefixLength (Unsigned32 (0..128))
          -- DESCRIPTION
          -- "An implementation is required to support
          --  global IPv4 and/or IPv6 addresses, depending
          --  on its support for IPv4 and IPv6."

          -- OBJECT  swmBGPNeighborInetAddressType
          -- SYNTAX  InetAddressType { ipv4(1), ipv6(2) }
          -- DESCRIPTION
          -- "An implementation is required to support
          --  global IPv4 and/or IPv6 addresses, depending
          --  on its support for IPv4 and IPv6."

          -- OBJECT  swmBGPNeighborInetAddress
          -- SYNTAX  InetAddress (SIZE(4|16))
          -- DESCRIPTION
          -- "An implementation is required to support
          --  global IPv4 and/or IPv6 addresses, depending
          --  on its support for IPv4 and IPv6."

      MODULE -- this module
      MANDATORY-GROUPS    {
                            swmSupportedTunnelGroup,
                            swmEncapsGroup,
                            swmBGPNeighborGroup
                          }
      ::= { swmCompliances 1 }

   swmSupportedTunnelGroup    OBJECT-GROUP
      OBJECTS {
          swmSupportedTunnelType
      }
      STATUS  current
      DESCRIPTION
          "The collection of objects that are used to show
          what kind of tunnel the AFBR supports."
      ::= { swmGroups 1 }

   swmEncapsGroup    OBJECT-GROUP
      OBJECTS {
           swmEncapsIIPDst,



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           swmEncapsIIPDstType
      }
      STATUS  current
      DESCRIPTION
          "The collection of objects that are used to display
          softwire mesh encapsulation information."
      ::= { swmGroups 2 }

   swmBGPNeighborGroup    OBJECT-GROUP
      OBJECTS {
           swmBGPNeighborTunnelType
      }
      STATUS  current
      DESCRIPTION
          "The collection of objects that are used to display
           softwire mesh BGP neighbor information."
      ::= { swmGroups 3 }

   END

7.  Security Considerations

   Because this MIB module reuses the IP Tunnel MIB, the security
   considerations of the IP Tunnel MIB are also applicable to the
   Softwire Mesh MIB.

   There are no management objects defined in this MIB module that have
   a MAX-ACCESS clause of read-write and/or read-create.  So, if this
   MIB module is implemented correctly, then there is no risk that an
   intruder can alter or create any management objects of this MIB
   module via direct SNMP SET operations.

   Some of the readable objects in this MIB module (i.e., objects with a
   MAX-ACCESS other than not-accessible) may be considered sensitive or
   vulnerable in some network environments.  It is thus important to
   control even GET and/or NOTIFY access to these objects and possibly
   to even encrypt the values of these objects when sending them over
   the network via SNMP.  These are the objects and their sensitivity/
   vulnerability:

   swmSupportedTunnelType, swmEncapsIIPDstType, swmEncapsIIPDst, and
   swmBGPNeighborTunnelType can expose the types of tunnels used within
   the internal network and potentially reveal the topology of the
   internal network.







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   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.

   Implementations SHOULD provide the security features described by the
   SNMPv3 framework (see [RFC3410]), and implementations claiming
   compliance to the SNMPv3 standard MUST include full support for
   authentication and privacy via the User-based Security Model (USM)
   [RFC3414] with the AES cipher algorithm [RFC3826].  Implementations
   MAY also provide support for the Transport Security Model (TSM)
   [RFC5591] in combination with a secure transport such as SSH
   [RFC5592] or TLS/DTLS [RFC6353].

   Further, deployment of SNMP versions prior to SNMPv3 is NOT
   RECOMMENDED.  Instead, it is RECOMMENDED to deploy SNMPv3 and to
   enable cryptographic security.  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 indeed GET or SET (change/create/delete) them.

8.  IANA Considerations

   IANA has allocated the following OBJECT IDENTIFIER value and recorded
   it in the SMI Numbers registry in the subregistry called "SMI Network
   Management MGMT Codes Internet-standard MIB" under the mib-2 branch
   (1.3.6.1.2.1):

           Descriptor        OBJECT IDENTIFIER value
           ----------        -----------------------
           swmMIB            { mib-2 239 }

   IANA has recorded the following IANAtunnelType Textual Convention
   within the IANAifType-MIB:

           IANAtunnelType ::= TEXTUAL-CONVENTION
                 SYNTAX     INTEGER {
                            softwireMesh(16)  -- softwire mesh tunnel
                            }










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9.  References

9.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC2578]  McCloghrie, K., Ed., Perkins, D., Ed., and J.
              Schoenwaelder, Ed., "Structure of Management Information
              Version 2 (SMIv2)", STD 58, RFC 2578,
              DOI 10.17487/RFC2578, April 1999,
              <http://www.rfc-editor.org/info/rfc2578>.

   [RFC2579]  McCloghrie, K., Ed., Perkins, D., Ed., and J.
              Schoenwaelder, Ed., "Textual Conventions for SMIv2",
              STD 58, RFC 2579, DOI 10.17487/RFC2579, April 1999,
              <http://www.rfc-editor.org/info/rfc2579>.

   [RFC2580]  McCloghrie, K., Ed., Perkins, D., Ed., and J.
              Schoenwaelder, Ed., "Conformance Statements for SMIv2",
              STD 58, RFC 2580, DOI 10.17487/RFC2580, April 1999,
              <http://www.rfc-editor.org/info/rfc2580>.

   [RFC3414]  Blumenthal, U. and B. Wijnen, "User-based Security Model
              (USM) for version 3 of the Simple Network Management
              Protocol (SNMPv3)", STD 62, RFC 3414,
              DOI 10.17487/RFC3414, December 2002,
              <http://www.rfc-editor.org/info/rfc3414>.

   [RFC3826]  Blumenthal, U., Maino, F., and K. McCloghrie, "The
              Advanced Encryption Standard (AES) Cipher Algorithm in the
              SNMP User-based Security Model", RFC 3826,
              DOI 10.17487/RFC3826, June 2004,
              <http://www.rfc-editor.org/info/rfc3826>.

   [RFC4001]  Daniele, M., Haberman, B., Routhier, S., and J.
              Schoenwaelder, "Textual Conventions for Internet Network
              Addresses", RFC 4001, DOI 10.17487/RFC4001, February 2005,
              <http://www.rfc-editor.org/info/rfc4001>.

   [RFC5512]  Mohapatra, P. and E. Rosen, "The BGP Encapsulation
              Subsequent Address Family Identifier (SAFI) and the BGP
              Tunnel Encapsulation Attribute", RFC 5512,
              DOI 10.17487/RFC5512, April 2009,
              <http://www.rfc-editor.org/info/rfc5512>.




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   [RFC5565]  Wu, J., Cui, Y., Metz, C., and E. Rosen, "Softwire Mesh
              Framework", RFC 5565, DOI 10.17487/RFC5565, June 2009,
              <http://www.rfc-editor.org/info/rfc5565>.

   [RFC5566]  Berger, L., White, R., and E. Rosen, "BGP IPsec Tunnel
              Encapsulation Attribute", RFC 5566, DOI 10.17487/RFC5566,
              June 2009, <http://www.rfc-editor.org/info/rfc5566>.

   [RFC5591]  Harrington, D. and W. Hardaker, "Transport Security Model
              for the Simple Network Management Protocol (SNMP)",
              STD 78, RFC 5591, DOI 10.17487/RFC5591, June 2009,
              <http://www.rfc-editor.org/info/rfc5591>.

   [RFC5592]  Harrington, D., Salowey, J., and W. Hardaker, "Secure
              Shell Transport Model for the Simple Network Management
              Protocol (SNMP)", RFC 5592, DOI 10.17487/RFC5592, June
              2009, <http://www.rfc-editor.org/info/rfc5592>.

   [RFC6353]  Hardaker, W., "Transport Layer Security (TLS) Transport
              Model for the Simple Network Management Protocol (SNMP)",
              STD 78, RFC 6353, DOI 10.17487/RFC6353, July 2011,
              <http://www.rfc-editor.org/info/rfc6353>.

9.2.  Informative References

   [RFC2863]  McCloghrie, K. and F. Kastenholz, "The Interfaces Group
              MIB", RFC 2863, DOI 10.17487/RFC2863, June 2000,
              <http://www.rfc-editor.org/info/rfc2863>.

   [RFC3410]  Case, J., Mundy, R., Partain, D., and B. Stewart,
              "Introduction and Applicability Statements for Internet-
              Standard Management Framework", RFC 3410,
              DOI 10.17487/RFC3410, December 2002,
              <http://www.rfc-editor.org/info/rfc3410>.

   [RFC4087]  Thaler, D., "IP Tunnel MIB", RFC 4087,
              DOI 10.17487/RFC4087, June 2005,
              <http://www.rfc-editor.org/info/rfc4087>.

   [RFC4925]  Li, X., Ed., Dawkins, S., Ed., Ward, D., Ed., and A.
              Durand, Ed., "Softwire Problem Statement", RFC 4925,
              DOI 10.17487/RFC4925, July 2007,
              <http://www.rfc-editor.org/info/rfc4925>.








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Acknowledgements

   The authors would like to thank Dave Thaler, Jean-Philippe Dionne, Qi
   Sun, Sheng Jiang, and Yu Fu for their valuable comments.

Authors' Addresses

   Yong Cui
   Tsinghua University
   Department of Computer Science, Tsinghua University
   Beijing  100084
   China

   Phone: +86-10-6260-3059
   Email: yong@csnet1.cs.tsinghua.edu.cn


   Jiang Dong
   Tsinghua University
   Department of Computer Science, Tsinghua University
   Beijing  100084
   China

   Phone: +86-10-6278-5822
   Email: knight.dongjiang@gmail.com


   Peng Wu
   Tsinghua University
   Department of Computer Science, Tsinghua University
   Beijing  100084
   China

   Phone: +86-10-6278-5822
   Email: weapon9@gmail.com


   Mingwei Xu
   Tsinghua University
   Department of Computer Science, Tsinghua University
   Beijing  100084
   China

   Phone: +86-10-6278-5822
   Email: xmw@cernet.edu.cn






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   Antti Yla-Jaaski
   Aalto University
   Konemiehentie 2
   Espoo  02150
   Finland

   Phone: +358-40-5954222
   Email: antti.yla-jaaski@aalto.fi











































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