Softwire Working Group Q. Sun Internet-Draft H. Wang Intended status: Standards Track Y. Cui Expires: April 8, 2016 Tsinghua University I. Farrer Deutsche Telekom AG M. Boucadair France Telecom R. Asati Cisco Systems, Inc. October 6, 2015 YANG Data Model for IPv4-in-IPv6 Softwire draft-sun-softwire-yang-04 Abstract This document defines a YANG data model for the configuration and management of IPv4-in-IPv6 Softwire Border Routers and Customer Premises Equipment. It covers the Lightweight 4over6, MAP-E and MAP-T Softwire mechanisms. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on April 8, 2016. Sun, et al. Expires April 8, 2016 [Page 1] Internet-Draft YANG for softwire October 2015 Copyright Notice Copyright (c) 2015 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 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. YANG Tree Diagrams . . . . . . . . . . . . . . . . . . . 3 1.3. YANG Modelling of NAT44 Functionality . . . . . . . . . . 4 2. Objectives . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1. Common . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2. Lightweight 4over6 . . . . . . . . . . . . . . . . . . . 5 2.3. MAP-E . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.4. MAP-T . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Softwire YANG Tree Diagrams . . . . . . . . . . . . . . . . . 5 3.1. Common Tree Diagrams . . . . . . . . . . . . . . . . . . 5 3.2. Lightweight 4over6 Tree Diagrams . . . . . . . . . . . . 6 3.3. MAP-E Tree Diagrams . . . . . . . . . . . . . . . . . . . 8 3.4. MAP-T Tree Diagrams . . . . . . . . . . . . . . . . . . . 10 3.5. Notifications for Softwire YANG . . . . . . . . . . . . . 12 4. Softwire YANG Model . . . . . . . . . . . . . . . . . . . . . 12 5. Example of Configure Lw4over6 Binding-Table . . . . . . . . . 30 6. Security Considerations . . . . . . . . . . . . . . . . . . . 31 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 32 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 32 9.1. Normative References . . . . . . . . . . . . . . . . . . 32 9.2. Informative References . . . . . . . . . . . . . . . . . 33 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 34 1. Introduction The IETF Softwire Working Group has developed several IPv4-in-IPv6 Softwire mechanisms to address various deployment contexts and constraints. As a companion to the architectural specification documents, this document focuses on the provisioning of softwire Sun, et al. Expires April 8, 2016 [Page 2] Internet-Draft YANG for softwire October 2015 functional elements: Border Routers (BRs) and Customer Premises Equipment (CPEs). This document defines a YANG data model that can be used to configure and manage IPv4-in-IPv6 Softwire BRs and/or CEs via NETCONF protocol[RFC6241]. To ensure interoperability in mixed vendors environments, it is important that the models can be easily reused between different vendors and implementations. There are three different mechanisms in this YANG model. Each specific mechanism has their separate YANG modules respectively: o Lightweight 4over6 [RFC7596] o MAP-E [RFC7597] o MAP-T [RFC7599] This model is structured into two root containers: 1. Container "softwire-config" holds the collection of YANG definitions common to all softwire configuration of BRs and CEs. 2. Container "softwire-state" holds YANG definitions for the operational state of the Softwire BRs and CEs. The model also includes a notification module. The aim is to notify the client that a specific status has been changed. This approach has been taken so that the model can be easily extended in the future to support additional softwire mechanisms, should this be necessary. 1.1. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. The reader should be familiar with the terms defined in [RFC7596] [RFC7597] [RFC7599] , and the YANG data modelling language [RFC6020]. 1.2. YANG Tree Diagrams The Softwire YANG tree diagrams provide a concise representation of the YANG modules to help the reader understand the module structure. The meaning of the symbols in these diagrams are as follows: Sun, et al. Expires April 8, 2016 [Page 3] Internet-Draft YANG for softwire October 2015 o Brackets "[" and "]" enclose list keys. o Braces "{" and "}" enclose feature content. o Parentheses "(" and ")" enclose choice and case nodes, and case nodes are also marked with a colon (":"). o Symbols after data node names: "?" means an optional node, and "*" denotes a list and leaf-list. o Abbreviations before data node names: "rw" means configuration data (read-write), and "ro" means state data (read-only). 1.3. YANG Modelling of NAT44 Functionality This documented model does not include NAT-specific provisioning parameters other than the external IP address and port set which a softwire client may use for NAT44. Additional NAT-specific considerations are out of scope of this document. A YANG model for the configuration and management of NAT gateways is described in [I-D.sivakumar-yang-nat]. 2. Objectives This document defines a YANG data model that can be used to configure and manage BRs and CEs for the following IPv4-in-IPv6 Softwire mechanisms: Lightweight 4over6, MAP-E and MAP-T. For Lightweight 4over6, the configuration and management information of lwB4 and lwAFTR are different. The lwAFTR needs to maintain a binding table of configured lwB4s. The lwB4 holds the configuration for its local tunnel, the lwAFTR address and a NAPT table of active translations. For the MAP-E and MAP-T, CE and BR both need to maintain the map-rule table. Thus, there is no need to distinguish BR and CE. 2.1. Common The common model abstracts the shared features of different BRs and CEs making a single node softwire description for common features. The following sections of the document are structured with the root of the softwire YANG model (common to all mechanisms) described first. The subsequent sections describe the models relevant to the different softwire mechanisms. All functions are listed, but the YANG models use the "feature" statement to distinguish among the different softwire mechanisms. Sun, et al. Expires April 8, 2016 [Page 4] Internet-Draft YANG for softwire October 2015 2.2. Lightweight 4over6 Lightweight 4over6 includes two elements: lwAFTR and lwB4. The lwAFTR holds configuration for IPv4-IPv6 address bindings which is used for the forwarding of traffic originating from lwB4s. And the lwB4 is configured with the relevant parameters for establishing the IPv4 in IPv6 tunnel including an IPv6 address for the lwAFTR and the IPv4 configuration for NAPT44. 2.3. MAP-E MAP-E elements (BR and CE) are provisioned with the MAP rules necessary for defining MAP domains and forwarding rules. 2.4. MAP-T MAP-T elements (BR and CE) are provisioned with the MAP rules necessary for defining MAP domains and forwarding rules. MAP-T CEs an additional "ipv6-prefix" parameter is also configured. 3. Softwire YANG Tree Diagrams 3.1. Common Tree Diagrams Figure 1 describes the softwire data model which is common to all of the different softwire mechanisms listed in Section 1: +--rw softwire-config | +--rw description? string | +--rw lw4over6 {lw4over6}? | | +--rw lwaftr {lwaftr}? | | +--rw lwb4 {lwb4}? | +--rw map-e {map-e}? | +--rw map-t {map-t}? | +--ro softwire-state +--ro description? string +--ro lw4over6 {lw4over6}? | +--ro lwaftr {lwaftr}? | +--ro lwb4 {lwb4}? +--ro map-e {map-e}? +--ro map-t {map-t}? Figure 1: Softwire Common Data Model Structure The mechanism specific models for lw4over6, MAP-E and MAP-T are described in detail in the following sections. Sun, et al. Expires April 8, 2016 [Page 5] Internet-Draft YANG for softwire October 2015 3.2. Lightweight 4over6 Tree Diagrams Figure 2 defines the softwire data model for Lightweight 4over6 which includes lwAFR and lwB4: module: ietf-softwire +--rw softwire-config | +--... | +--rw lw4over6 {lw4over6}? | +--rw lwaftr {lwaftr}? | | +--rw enable? boolean | | +--rw lwaftr-instances | | +--rw lwaftr-instance* [id] | | +--rw id uint32 | | +--rw name? string | | +--rw softwire-num-threshold uint32 | | +--rw tunnel-mtu uint16 | | +--rw fragment-mru uint16 | | +--rw binding-table | | +--rw binding-entry* [binding-ipv6info] | | +--rw binding-ipv6info union | | +--rw binding-ipv4-addr inet:ipv4-address | | +--rw port-set | | | +--rw offset uint8 | | | +--rw psid uint16 | | | +--rw psid-len uint8 | | +--rw lwaftr-ipv6-addr inet:ipv6-address | | +--rw lifetime? uint32 | +--rw lwb4 {lwb4}? | +--rw enable? boolean | +--rw lwb4-instances | +--rw lwb4-instance* [binding-ipv6info] | +--rw name? string | +--rw tunnel-mtu uint16 | +--rw fragment-mru uint16 | +--rw b4-ipv6-addr-format boolean | +--rw binding-ipv6info union | +--rw binding-ipv4-addr inet:ipv4-address | +--rw port-set | | +--rw offset uint8 | | +--rw psid uint16 | | +--rw psid-len uint8 | +--rw lwaftr-ipv6-addr inet:ipv6-address | +--rw lifetime? uint32 +--ro softwire-state +--... +--ro lw4over6 {lw4over6}? +--ro lwaftr {lwaftr}? Sun, et al. Expires April 8, 2016 [Page 6] Internet-Draft YANG for softwire October 2015 | +--ro lwaftr-instances | +--ro lwaftr-instance* [id] | +--ro id uint32 | +--ro name? string | +--ro sentPacket? yang:zero-based-counter64 | +--ro sentByte? yang:zero-based-counter64 | +--ro rcvdPacket? yang:zero-based-counter64 | +--ro rcvdByte? yang:zero-based-counter64 | +--ro droppedPacket? yang:zero-based-counter64 | +--ro droppedByte? yang:zero-based-counter64 | +--ro active-softwire-num? uint32 | +--ro binding-table | +--ro binding-entry* [binding-ipv6info] | +--ro binding-ipv6info union | +--ro active? boolean +--ro lwb4 {lwb4}? +--ro lwb4-instances +--ro lwb4-instance* [binding-ipv6info] +--ro name? string +--ro binding-ipv6info union +--ro sentPacket? yang:zero-based-counter64 +--ro sentByte? yang:zero-based-counter64 +--ro rcvdPacket? yang:zero-based-counter64 +--ro rcvdByte? yang:zero-based-counter64 +--ro droppedPacket? yang:zero-based-counter64 +--ro droppedByte? yang:zero-based-counter64 Figure 2: Softwire Lightweight 4over6 Data Model Structure Some of the important lwAFTR nodes: o binding-entry: used to define the binding relationship between 3-tuples, which contains the lwB4's IPv6 address, the allocated IPv4 address and restricted port-set. For detail information, please refer to [RFC7596]. o tunnel-mtu: used to set the value of MTU for the Lightweight 4over6 tunnel. o fragment-mru: used to set the value of fragment for Lightweight 4over6 tunnel. o tunnel-num-threshold: used to set the maximum number of tunnels that can be created on the lw4over6 device simultaneously. o active-tunnel-num (ro): used to present the number of tunnels currently provisioned on the device. Sun, et al. Expires April 8, 2016 [Page 7] Internet-Draft YANG for softwire October 2015 o active (ro): used to show the status of particular binding-entry. Some of the important lwB4 nodes: o b4-ipv6-addr-format: indicates the format of lwB4 IPv6 address. If set to true, it indicates that the IPv6 source address of the lwB4 is constructed according to the description in [RFC7596]; if set to false, the lwB4 can use any /128 address from the assigned IPv6 prefix. o binding-ipv6info: used to set the IPv6 address type which is combined in a binding entry, for a complete address or a prefix. 3.3. MAP-E Tree Diagrams Figure 3 defines the softwire data model for MAP-E: Sun, et al. Expires April 8, 2016 [Page 8] Internet-Draft YANG for softwire October 2015 module: ietf-softwire +--rw softwire-config | +--... | +--rw map-e {map-e}? | +--rw enable? boolean | +--rw map-e-instances | +--rw map-e-instance* [id] | +--rw id uint32 | +--rw name? string | +--rw map-rules | | +--rw map-rule* [id] | | +--rw id uint8 | | +--rw forwarding boolean | | +--rw rule-ipv6-prefix inet:ipv6-prefix | | +--rw rule-ipv4-prefix inet:ipv4-prefix | | +--rw port-set | | | +--rw offset uint8 | | | +--rw psid uint16 | | | +--rw psid-len uint8 | | +--rw ea-len uint8 | +--rw tunnel-mtu uint16 | +--rw fragment-mru uint16 | +--rw br-ipv6-addr inet:ipv6-address +--ro softwire-state +--... +--ro map-e {map-e}? +--ro map-e-instances +--ro map-e-instance* [id] +--ro id int32 +--ro name? string +--ro sentPacket? yang:zero-based-counter64 +--ro sentByte? yang:zero-based-counter64 +--ro rcvdPacket? yang:zero-based-counter64 +--ro rcvdByte? yang:zero-based-counter64 +--ro droppedPacket? yang:zero-based-counter64 +--ro droppedByte? yang:zero-based-counter64 Figure 3: Softwire MAP-E Data Model Structure Some of the important MAP-E nodes: o forwarding: This parameter specifies whether the rule is to be used for forwarding (FMR). If set, this rule is used as an FMR; if not set, this rule is a BMR only and MUST NOT be used for forwarding. See Section 4.1 [RFC7598]. o offset: used to set the number of offset bits. Sun, et al. Expires April 8, 2016 [Page 9] Internet-Draft YANG for softwire October 2015 o psid: used to algorithmically identify a set of ports exclusively for a specific softwire. o ea-len: used to set the length of the Embedded-Address (EA), which defined in the mapping rule for a MAP domain. o tunnel-mtu: used to set the value of MTU for MAP-E tunnel. o fragment-mru: used to the value of fragment for MAP-E tunnel. o stat-count (ro): use to show the numbers of packets and bytes information of specific device respectively. 3.4. MAP-T Tree Diagrams Figure 4 defines the softwire data model for MAP-T: Sun, et al. Expires April 8, 2016 [Page 10] Internet-Draft YANG for softwire October 2015 module: ietf-softwire +--rw softwire-config | +--... | +--rw map-t {map-t}? | +--rw enable? boolean | +--rw map-t-instances | +--rw map-t-instance* [id] | +--rw id uint32 | +--rw name? string | +--rw map-rules | | +--rw map-rule* [id] | | +--rw id uint8 | | +--rw forwarding boolean | | +--rw rule-ipv6-prefix inet:ipv6-prefix | | +--rw rule-ipv4-prefix inet:ipv4-prefix | | +--rw port-set | | | +--rw offset uint8 | | | +--rw psid uint16 | | | +--rw psid-len uint8 | | +--rw ea-len uint8 | +--rw dmr-ipv6-prefix? inet:ipv6-prefix +--ro softwire-state +--... +--ro map-t {map-t}? +--ro map-t-instances +--ro map-t-instance* [id] +--ro id int32 +--ro name? string +--ro sentPacket? yang:zero-based-counter64 +--ro sentByte? yang:zero-based-counter64 +--ro rcvdPacket? yang:zero-based-counter64 +--ro rcvdByte? yang:zero-based-counter64 +--ro droppedPacket? yang:zero-based-counter64 +--ro droppedByte? yang:zero-based-counter64 Figure 4: Softwire MAP-T Data Model Structure Some of the important MAP-T nodes: o dmr-ipv6-prefix: defines the DMR in MAP-T. This parameter is optional when configuring a MAP-T BR. o stat-count (ro): use to show the numbers of packets and bytes information of specific device respectively. Sun, et al. Expires April 8, 2016 [Page 11] Internet-Draft YANG for softwire October 2015 3.5. Notifications for Softwire YANG This section describes the diagram tree for the notifications. These notifications pertain to configuration and monitoring portions of specific Softwire mechanisms. The logic is that, the softwire instance notifies the NETCONF client with the index for a mapping entry and then the NETCONF client retrieves the related information from the operational datastore of that instance. module: ietf-softwire notifications: +---n softwire-lwaftr-event {lw4over6,lwaftr}? | +--ro lwaftr-id? -> /softwire-state/lw4over6/lwaftr/.../id | +--ro invalid-entry* -> /softwire-config/lw4over6/lwaftr/.../binding-table/binding-entry/binding-ipv6info | +--ro added-entry* inet:ipv6-address | +--ro modified-entry* -> /softwire-config/lw4over6/lwaftr/.../binding-table/binding-entry/binding-ipv6info +---n softwire-lwb4-event {lw4over6,lwb4}? | +--ro lwb4-binding-ipv6-addr-change inet:ipv6-address +---n softwire-map-e-event {map-e}? | +--ro map-e-id -> /softwire-config/map-e/.../id | +--ro invalid-entry-id* -> /softwire-config/map-e/.../map-rules/map-rule/id | +--ro added-entry* uint32 | +--ro modified-entry* -> /softwire-config/map-e/.../map-rules/map-rule/id +---n softwire-map-t-event {map-t}? +--ro map-t-id -> /softwire-config/map-t/.../id +--ro invalid-entry-id* -> /softwire-config/map-t/.../map-rules/map-rule/id +--ro added-entry* uint32 +--ro modified-entry* -> /softwire-config/map-t/.../map-rules/map-rule/id Figure 5: Softwire Notifications Data Model Structure Some of the important notification nodes: o invalid-entry, added-entry, modified-entry: used to notify the client that a specific binding entry or MAP rule is expired/ invalid, added, or modified. o lwb4-binding-ipv6-addr-change: use to notify that the lwB4's binding-ipv6-address has been changed or the value of the 'b4-ipv6-addr-format' is "false". 4. Softwire YANG Model This module imports typedefs from [RFC6991]. file "ietf-softwire@2015-08-31.yang" module ietf-softwire { Sun, et al. Expires April 8, 2016 [Page 12] Internet-Draft YANG for softwire October 2015 namespace "urn:ietf:params:xml:ns:yang:ietf-softwire"; prefix "softwire"; import ietf-inet-types {prefix inet; } import ietf-yang-types {prefix yang; } organization "Softwire Working Group"; contact " Qi Sun sunqi.ietf@gmail.com Hao Wang wangh13@mails.tsinghua.edu.cn Yong Cui yong@csnet1.cs.tsinghua.edu.cn Ian Farrer ian.farrer@telekom.de Mohamed Boucadair mohamed.boucadair@orange.com Rajiv Asati rajiva@cisco.com "; description "This document defines a YANG data model for the configuration and management of IPv4-in-IPv6 Softwire Border Routers and Customer Premises Equipment. It covers Lightweight 4over6, MAP-E and MAP-T Softwire mechanisms. Copyright (c) 2014 IETF Trust and the persons identified as authors of the code. All rights reserved. This version of this YANG module is part of RFC XXX; see the RFC itself for full legal notices."; revision 2015-09-30 { description "Version-04: fix YANG syntax; Add flags to map-rule; Remove the map-rule-type element. "; reference "tbc"; } revision 2015-04-07 { description "Version-03: Integrate lw4over6; Updata state nodes; Correct grammar errors; Reuse groupings; Update descriptions. Simplify the model."; reference "tbc"; } revision 2015-02-10 { description "Version-02: Add notifications."; reference "tbc"; Sun, et al. Expires April 8, 2016 [Page 13] Internet-Draft YANG for softwire October 2015 } revision 2015-02-06 { description "Version-01: Correct grammar errors; Reuse groupings; Update descriptions."; reference "tbc"; } revision 2015-02-02 { description "Initial revision."; reference "tbc"; } /* * Features */ feature lw4over6 { description "Lightweight 4over6 (lw4over6) is an IPv4-over-IPv6 tunnelling transition mechanism. Lightweight 4over6 is a solution designed specifically for complete independence between IPv6 subnet prefix (and /128 IPv6 address) and IPv4 address with or without IPv4 address sharing. This is accomplished by maintaining state for each softwire (per-subscriber state) in the central lwAFTR and a hub-and-spoke forwarding architecture. In order to delegate the NAPT function and achieve IPv4 address sharing, port-restricted IPv4 addresses needs to be allocated to CEs."; reference "I-D.ietf-softwire-lw4over6"; } feature lwaftr { if-feature lw4over6; description "The AFTRs (BRs) for Lightweight 4over6, so-called lwAFTR. This feature indicates that a instance functions as a lwAFTR. A lwAFTR is an IPv4-in-IPv6 tunnel concentrator that maintains per-subscriber IPv4-IPv6 address binding."; } feature lwb4 { Sun, et al. Expires April 8, 2016 [Page 14] Internet-Draft YANG for softwire October 2015 if-feature lw4over6; description "The B4s (CEs) for Lightweight 4over6, so-called lwB4. This feature indicates that a instance functions as a lwB4. A lwB4 is an IPv4-in-IPv6 tunnel initiator. It is dual-stack capable node, either a directly connected end-host or a CE. It sources IPv4 conncections using the configured port-set and the public IPv4 address."; } feature map-e { description "MAP-E is an IPv6 transition mechanism for transporting IPv4 packets across an IPv6 network using IP encapsulation. MAP-E allows for a reduction of the amount of centralized state using rules to express IPv4/IPv6 address mappings. This introduces an algorithmic relationship between the IPv6 subnet and IPv4 address. This relationship also allows the option of direct, meshed connectivity between users. Alternatively, MAP-E can be configured to support IPv4/IPv6 indepent binding. This feature indicates the instance functions as a MAP-E instance."; reference "I-D.ietf-softwire-map"; } feature map-t { description "The Mapping of Address and Port - Translation (MAP-T) architecture is a double stateless NAT64 based solution. It uses the stateless algorithmic address & transport layer port mapping scheme defined in MAP-E. The MAP-T solution differs from MAP-E in the use of IPv4-IPv6 translation, rather than encapsulation, as the form of IPv6 domain transport. This feature indicates the instance functions as a MAP-T instance. "; reference "I-D.ietf-softwire-map-t"; } /* * Grouping */ grouping port-set { description "Use the PSID algorithm to represent a range of transport layer Sun, et al. Expires April 8, 2016 [Page 15] Internet-Draft YANG for softwire October 2015 ports."; leaf offset { type uint8 { range 0..16; } mandatory true; description "The number of offset bits. In Lightweight 4over6, the defaul value is 0 for assigning one contiguous port range. In MAP-E/T, the default value is 6, which excludes system ports by default and assigns distributed port ranges. If the this parameter is larger than 0, the value of offset MUST be greater than 0."; } leaf psid { type uint16; mandatory true; description "Port Set Identifier (PSID) value, which identifies a set of ports algorithmically."; } leaf psid-len { type uint8 { range 0..16; } mandatory true; description "The length of PSID, representing the sharing ratio for an IPv4 address."; } } grouping binding-entry { description "The lwAFTR maintains an address binding table that contains thebinding between the lwB4's IPv6 address, the allocated IPv4 address and restricted port-set."; leaf binding-ipv6info { type union { type inet:ipv6-address; type inet:ipv6-prefix; } mandatory true; description "The IPv6 information for a binding entry. If it's an IPv6 prefix, it indicates that the IPv6 source address of the lwB4 is constructed according to the description in RFC7596; if it's an IPv6 address, it means the lwB4 uses Sun, et al. Expires April 8, 2016 [Page 16] Internet-Draft YANG for softwire October 2015 any /128 address from the assigned IPv6 prefix. "; } leaf binding-ipv4-addr { type inet:ipv4-address; mandatory true; description "The IPv4 address assigned to the lwB4, which is used as the IPv4 external address for lwB4 local NAPT44."; } container port-set { description "For Lightweight 4over6, the default value of offset should be 0, to configure one contiguous port range."; uses port-set { refine offset { default "0"; } } } leaf lwaftr-ipv6-addr { type inet:ipv6-address; mandatory true; description "The IPv6 address for lwaftr."; } leaf lifetime { type uint32; units seconds; description "The lifetime for the binding entry"; } } /* grouping nat-table { description "Grouping 'nat-table' is not extended. The current mechanism isfocusing on the provisioning of external IP address and port set; other NAT-specific considerations are out of scope for this model."; } */ grouping map-instance { description "A map-instance could be a MAP-CE or a MAP-BR"; Sun, et al. Expires April 8, 2016 [Page 17] Internet-Draft YANG for softwire October 2015 leaf id { type uint32; mandatory true; description "MAP Instance ID"; } leaf name { type string; description "MAP Instance Name"; } container map-rules { description "A MAP instance could be configured with multiple sets of MAP rules"; list map-rule { key "id"; description "A set of parameters describing the mapping between an IPv4 prefix, IPv4 address or shared IPv4 address and an IPv6 prefix or address. Each domain uses a differe mapping rule set."; leaf id { type uint8; description "Rule ID"; } leaf forwarding { type boolean; mandatory true; description "This parameter specifies whether the rule may be used for forwarding (FMR). If set, this rule is used as an FMR; if not set, this rule is a BMR only and MUST NOT be used for forwarding."; } /***** leaf map-rule-type { mandatory true; type enumeration { enum "BMR"; enum "FMR"; } description "The BMR and FMR share the rule format. BMR is used for a node to configure itself with IPv4 information retrived from the rule. FMR is designed for the in-domain 4-in-6 routing, used in mesh mode. A BMR can be FMR in some case. The DMR for map-t is defined separately."; Sun, et al. Expires April 8, 2016 [Page 18] Internet-Draft YANG for softwire October 2015 } *****/ leaf rule-ipv6-prefix { type inet:ipv6-prefix; mandatory true; description "The Rule IPv6 prefix defined in the mapping rule."; } leaf rule-ipv4-prefix { type inet:ipv4-prefix; mandatory true; description "The Rule IPv4 prefix defined in the mapping rule."; } container port-set { description "Port set parameters specify a set of port ranges. For MAP, the default value of offset is 6. "; uses port-set { refine offset { default "6"; } } } leaf ea-len { type uint8; mandatory true; description "Embedded Address (EA) bits are the IPv4 EA-bits in the IPv6 address identify an IPv4 prefix/address (or part thereof) or a shared IPv4 address (or part thereof) and a port-set dentifier. The length of the EA-bits is defined as part of a MAP rule for a MAP domain."; } } } } grouping traffic-stat { description "Traffic statistics"; leaf sentPacket { type yang:zero-based-counter64; description "Number of packets sent."; } leaf sentByte { type yang:zero-based-counter64; description "Traffic sent, in bytes"; Sun, et al. Expires April 8, 2016 [Page 19] Internet-Draft YANG for softwire October 2015 } leaf rcvdPacket { type yang:zero-based-counter64; description "Number of packets received."; } leaf rcvdByte { type yang:zero-based-counter64; description "Traffic received, in bytes"; } leaf droppedPacket { type yang:zero-based-counter64; description "Number of packets dropped."; } leaf droppedByte { type yang:zero-based-counter64; description "Traffic dropped, in bytes"; } } /* * Configuration Data Nodes */ container softwire-config { description "The configuration data for Softwire instances. And the shared data describes the softwire data model which is common to all of the different softwire mechanisms, such as description."; leaf description { type string; description "A textual description of Softwire."; } container lw4over6 { if-feature lw4over6; description "lw4over6 configuration."; container lwaftr { if-feature lwaftr; description "Indicate this instance supports the lwAFTR function. The instances advertise the lwaftr feature through the capability exchange mechanism when a NETCONF session is established."; leaf enable { type boolean; Sun, et al. Expires April 8, 2016 [Page 20] Internet-Draft YANG for softwire October 2015 description "Enable/disable the lwAFTR function."; } container lwaftr-instances { description "A set of lwAFTRs to be configured."; list lwaftr-instance { key "id"; description "A set of lwAFTRs to be configured."; leaf id { type uint32; description "An instance identifier."; } leaf name { type string; description "The name for the lwaftr."; } leaf softwire-num-threshold { type uint32; mandatory true; description "The maximum number of tunnels that can be created on the lwAFTR."; } leaf tunnel-mtu { type uint16; mandatory true; description "The MTU for Lightweight 4over6 tunnel."; } leaf fragment-mru { type uint16; mandatory true; description "The fragmentation MRU for Lightweight 4over6 tunnel."; } container binding-table { description "id"; list binding-entry { key "binding-ipv6info"; description "id"; uses binding-entry; } } } } Sun, et al. Expires April 8, 2016 [Page 21] Internet-Draft YANG for softwire October 2015 } container lwb4 { if-feature lwb4; description "Indicate this instance supports the lwB4 function. The instances advertise the lwb4 feature through the capability exchange mechanism when a NETCONF session is established."; leaf enable { type boolean; description "Enable/disable the lwB4 function."; } container lwb4-instances { description "A set of lwB4s to be configured."; list lwb4-instance { key "binding-ipv6info"; description "id"; leaf name { type string; description "The lwb4 name."; } leaf tunnel-mtu { type uint16; mandatory true; description "The MTU for Lightweight 4over6 tunnel."; } leaf fragment-mru { type uint16; mandatory true; description "The fragment MRU for Lightweight 4over6 tunnel."; } leaf b4-ipv6-addr-format { type boolean; mandatory true; description "The format of lwB4 IPv6 address. If set to true, it indicates that the IPv6 source address of the lwB4 is constructed according to the description in [RFC7596]; if set to false, the lwB4 can use any /128 address from the assigned IPv6 prefix."; } uses binding-entry; Sun, et al. Expires April 8, 2016 [Page 22] Internet-Draft YANG for softwire October 2015 } } } } container map-e { if-feature map-e; description "Indicate the instances support the MAP-E function. The instances advertise the map-e feature through the capability exchange mechanism when a NETCONF session is established."; leaf enable { type boolean; default "true"; description "Enable/disable the MAP-E function."; } container map-e-instances { description "A set of MAP-E instances to be configured, applying to BRs and CEs."; list map-e-instance { key "id"; description "id"; uses map-instance; leaf tunnel-mtu { type uint16; mandatory true; description "The MTU for MAP-E tunnel."; } leaf fragment-mru { type uint16; mandatory true; description "The fragment MRU for MAP-E tunnel."; } leaf br-ipv6-addr { type inet:ipv6-address; mandatory true; description "The IPv6 address of the MAP-E BR."; } } } } container map-t { if-feature map-t; description Sun, et al. Expires April 8, 2016 [Page 23] Internet-Draft YANG for softwire October 2015 "Indicate the instances support the MAP-T function. The instances advertise the map-t feature through the capability exchange mechanism when a NETCONF session is established."; leaf enable { type boolean; default "true"; description "Enable/disable the MAP-T function."; } container map-t-instances { description "A set of the MAP-T instances to be configured, a pplying to BRs and CEs."; list map-t-instance { key "id"; description "id"; uses map-instance; leaf dmr-ipv6-prefix { type inet:ipv6-prefix; description "The IPv6 prefix of the MAP-T BR. "; } } } } } /* * Operational state Data Nodes */ container softwire-state { config false; description "The operational state data for Softwire instances. "; leaf description { type string; description "A textual description of the softwire instances."; } container lw4over6 { if-feature lw4over6; description "lw4over6 state."; container lwaftr { if-feature lwaftr; config false; description Sun, et al. Expires April 8, 2016 [Page 24] Internet-Draft YANG for softwire October 2015 "Indicate this instance supports the lwAFTR function. The instances advertise the lwaftr feature through the capability exchange mechanism when a NETCONF session is established."; container lwaftr-instances { description "A set of lwAFTRs."; list lwaftr-instance { key "id"; description "id"; leaf id { type uint32; description "id"; } leaf name { type string; description "The name for this lwaftr."; } uses traffic-stat; leaf active-softwire-num { type uint32; description "The number of currently active tunnels on the lw4over6 instance."; } container binding-table { description "id"; list binding-entry { key "binding-ipv6info"; description "An identifier of the binding entry."; leaf binding-ipv6info { type union { type inet:ipv6-address; type inet:ipv6-prefix; } mandatory true; description "The IPv6 information used to identify a binding entry. "; } leaf active { type boolean; description "Status of a specific tunnel."; } } } } Sun, et al. Expires April 8, 2016 [Page 25] Internet-Draft YANG for softwire October 2015 } } container lwb4 { if-feature lwb4; config false; description "Indicate this instance supports the lwB4 function. The instances advertise the lwb4 feature through the capability exchange mechanism when a NETCONF session is established."; container lwb4-instances { description "Status of the configured lwB4s."; list lwb4-instance { key "binding-ipv6info"; description "a lwB4 isntance."; leaf name { type string; description "The lwb4 name."; } leaf binding-ipv6info { type union { type inet:ipv6-address; type inet:ipv6-prefix; } mandatory true; description "The IPv6 information used to identify a binding entry. "; } uses traffic-stat; } } } } container map-e { if-feature map-e; config false; description "Indicate the instances support the MAP-E function. The instances advertise the map-e feature through the capability exchange mechanism when a NETCONF session is established."; container map-e-instances { description "Status of MAP-E instance(s)."; Sun, et al. Expires April 8, 2016 [Page 26] Internet-Draft YANG for softwire October 2015 list map-e-instance { key "id"; description "id"; leaf id { type int32; description "id"; } leaf name { type string; description "The map-e instance name."; } uses traffic-stat; } } } container map-t { if-feature map-t; config false; description "Indicate the instances support the MAP-T function. The instances advertise the map-t feature through the capability exchange mechanism when a NETCONF session is established."; container map-t-instances { description "Status of MAP-T instances."; list map-t-instance { key "id"; description "id"; leaf id { type int32; description ""; } leaf name { type string; description "The map-t instance name."; } uses traffic-stat; } } } } /* * Notifications */ Sun, et al. Expires April 8, 2016 [Page 27] Internet-Draft YANG for softwire October 2015 notification softwire-lwaftr-event { if-feature lw4over6; if-feature lwaftr; description "Notification for lwaftr."; leaf lwaftr-id { type leafref { path "/softwire-state/lw4over6/lwaftr/lwaftr-instances/" + "lwaftr-instance/id"; } description "id"; } leaf-list invalid-entry { type leafref { path "/softwire-config/lw4over6/lwaftr/lwaftr-instances/" + "lwaftr-instance[id=current()/../lwaftr-id]/" + "binding-table/binding-entry/binding-ipv6info"; } description "Notify the client that a specific binding entry has been expired/invalid. The binding-ipv6info identifies an entry."; } leaf-list added-entry { type inet:ipv6-address; description "Notify the client that a binding entry has been added. The ipv6 address of that entry is the index. The client get other information from the lwaftr about the entry indexed by that ipv6 address. "; } leaf-list modified-entry { type leafref { path "/softwire-config/lw4over6/lwaftr/lwaftr-instances/" + "lwaftr-instance[id=current()/../lwaftr-id]/" + "binding-table/binding-entry/binding-ipv6info"; } description "lwaftr"; } } notification softwire-lwb4-event { if-feature lw4over6; if-feature lwb4; description "lwB4 notification"; Sun, et al. Expires April 8, 2016 [Page 28] Internet-Draft YANG for softwire October 2015 leaf lwb4-binding-ipv6-addr-change { type inet:ipv6-address; mandatory true; description "The source tunnel IPv6 address of the lwB4. If 'b4-ipv6-addr-format' is false, or the lwb4's binding-ipv6-address changes for any reason, it SHOULD notify the NETCONF client."; } } notification softwire-map-e-event { if-feature map-e; description "Notifications for MAP-E."; leaf map-e-id { type leafref { path "/softwire-config/map-e/map-e-instances/map-e-instance/id"; } mandatory true; description "MAP-E event."; } leaf-list invalid-entry-id { type leafref { path "/softwire-config/map-e/map-e-instances/" + "map-e-instance[id=current()/../map-e-id]/map-rules/" + "map-rule/id"; } description "Invalid entry event."; } leaf-list added-entry { type uint32; description "Added entry."; } leaf-list modified-entry { type leafref { path "/softwire-config/map-e/map-e-instances/" + "map-e-instance[id=current()/../map-e-id]/map-rules/" + "map-rule/id"; } description "Modified entry."; } } notification softwire-map-t-event { if-feature map-t; Sun, et al. Expires April 8, 2016 [Page 29] Internet-Draft YANG for softwire October 2015 description "MAP-T notification"; leaf map-t-id { type leafref { path "/softwire-config/map-t/map-t-instances/map-t-instance/id"; } mandatory true; description "MAP-T ID"; } leaf-list invalid-entry-id { type leafref { path "/softwire-config/map-t/map-t-instances/" + "map-t-instance[id=current()/../map-t-id]/map-rules/" + "map-rule/id"; } description "Invalid Entry."; } leaf-list added-entry { type uint32; description "Added entry"; } leaf-list modified-entry { type leafref { path "/softwire-config/map-t/map-t-instances/" + "map-t-instance[id=current()/../map-t-id]/map-rules/" + "map-rule/id"; } description "Modified entry"; } } } 5. Example of Configure Lw4over6 Binding-Table The lwAFTR maintains an address binding table which contains the following 3-tuples: o IPv6 Address for a single lwB4 o Public IPv4 Address o Restricted port-set Sun, et al. Expires April 8, 2016 [Page 30] Internet-Draft YANG for softwire October 2015 The entry has two functions: the IPv6 encapsulation of inbound IPv4 packets destined to the lwB4 and the validation of outbound IPv4-in- IPv6 packets received from the lwB4 for de-capsulation. Requirement: Add an entry that maintain the relationship between 3-tuples of lwB4 (2001::1) in binding-table, which on the lwAFTR (2001::2). The data value of this 3-tuples are '2001::1', '123.1.1.1' and '1234' respectively. Here is the example binding-table configuration xml: 2001::2 123.1.1.1 1234 2001::1 1 Figure 6: Lw4over6 Binding-Table Configuration XML 6. Security Considerations The YANG module defined in this memo is designed to be accessed via the NETCONF protocol [RFC6241]. The lowest NETCONF layer is the secure transport layer and the mandatory to implement secure transport is SSH [RFC6242]. The NETCONF access control model [RFC6536] provides the means to restrict access for particular Sun, et al. Expires April 8, 2016 [Page 31] Internet-Draft YANG for softwire October 2015 NETCONF users to a pre-configured subset of all available NETCONF protocol operations and content. There are a number of data nodes defined in this YANG module which are writable/creatable/deletable (i.e. config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g. edit-config) to these data nodes without proper protection can have a negative effect on network operations. These are the subtrees and data nodes and their sensitivity/vulnerability: subtrees and data nodes and state why they are sensitive Some of thereadable data nodes in this YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g. via get, get-config or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability: subtrees and data nodes and state why they are sensitive 7. IANA Considerations A registry for standard YANG modules shall be set up. This document registers one URI for the YANG XML namespace in the IETF XML registry [RFC3688]. URI: urn:ietf:params:xml:ns:yang:softwire 8. Acknowledgements The authors would like to thank Lishan Li, Bert Wijnen, Giles Heron and Ole Troan for their contributions to this work. 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, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . Sun, et al. Expires April 8, 2016 [Page 32] Internet-Draft YANG for softwire October 2015 [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration Protocol (NETCONF) Access Control Model", RFC 6536, DOI 10.17487/RFC6536, March 2012, . [RFC7596] Cui, Y., Sun, Q., Boucadair, M., Tsou, T., Lee, Y., and I. Farrer, "Lightweight 4over6: An Extension to the Dual- Stack Lite Architecture", RFC 7596, DOI 10.17487/RFC7596, July 2015, . [RFC7597] Troan, O., Ed., Dec, W., Li, X., Bao, C., Matsushima, S., Murakami, T., and T. Taylor, Ed., "Mapping of Address and Port with Encapsulation (MAP-E)", RFC 7597, DOI 10.17487/RFC7597, July 2015, . [RFC7598] Mrugalski, T., Troan, O., Farrer, I., Perreault, S., Dec, W., Bao, C., Yeh, L., and X. Deng, "DHCPv6 Options for Configuration of Softwire Address and Port-Mapped Clients", RFC 7598, DOI 10.17487/RFC7598, July 2015, . [RFC7599] Li, X., Bao, C., Dec, W., Ed., Troan, O., Matsushima, S., and T. Murakami, "Mapping of Address and Port using Translation (MAP-T)", RFC 7599, DOI 10.17487/RFC7599, July 2015, . 9.2. Informative References [I-D.sivakumar-yang-nat] Sivakumar, S., Boucadair, M., and S. <>, "YANG Data Model for Network Address Translation (NAT)", draft-sivakumar- yang-nat-00 (work in progress), September 2015. Sun, et al. Expires April 8, 2016 [Page 33] Internet-Draft YANG for softwire October 2015 [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . Authors' Addresses Qi Sun Tsinghua University Beijing 100084 P.R. China Phone: +86-10-6278-5822 Email: sunqi.ietf@gmail.com Hao Wang Tsinghua University Beijing 100084 P.R. China Phone: +86-10-6278-5822 Email: wangh13@mails.tsinghua.edu.cn Yong Cui Tsinghua University Beijing 100084 P.R. China Phone: +86-10-6260-3059 Email: yong@csnet1.cs.tsinghua.edu.cn Ian Farrer Deutsche Telekom AG CTO-ATI,Landgrabenweg 151 Bonn, NRW 53227 Germany Email: ian.farrer@telekom.de Mohamed Boucadair France Telecom Rennes 35000 France Email: mohamed.boucadair@orange.com Sun, et al. Expires April 8, 2016 [Page 34] Internet-Draft YANG for softwire October 2015 Rajiv Asati Cisco Systems, Inc. 7025 Kit Creek Rd. RTP, NC 27709 USA Email: Rajiva@cisco.com Sun, et al. Expires April 8, 2016 [Page 35]