RFC 7856
Softwire Mesh Management Information Base (MIB)
Pages: 18
Proposed Standard
Proposed Standard
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.
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 . . . . . . . . . . . . . . . . . . . . . . . 171. 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
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.
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.
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].
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
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
"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
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
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 }
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
-- 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,
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.
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 }
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>.
[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>.
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
Antti Yla-Jaaski Aalto University Konemiehentie 2 Espoo 02150 Finland Phone: +358-40-5954222 Email: antti.yla-jaaski@aalto.fi