Softwire Working Group Q. Sun Internet-Draft H. Wang Intended status: Standards Track Y. Cui Expires: May 17, 2018 Tsinghua University I. Farrer S. Zechlin Deutsche Telekom AG M. Boucadair Orange R. Asati Cisco Systems, Inc. November 13, 2017 YANG Modules for IPv4-in-IPv6 Address plus Port Softwires draft-ietf-softwire-yang-03 Abstract This document defines YANG modules for the configuration and operation of IPv4-in-IPv6 softwire Border Relays and Customer Premises Equipment. The model 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 https://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 May 17, 2018. Sun, et al. Expires May 17, 2018 [Page 1] Internet-Draft YANG Module for A+P Softwires November 2017 Copyright Notice Copyright (c) 2017 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 (https://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 2. Overview of the Models . . . . . . . . . . . . . . . . . . . 3 2.1. Additional Configuration . . . . . . . . . . . . . . . . 4 3. Softwire YANG CE Tree Diagram . . . . . . . . . . . . . . . . 5 3.1. Softwire CE Tree Diagram Descriptions . . . . . . . . . . 7 4. Softwire BR YANG Tree Diagram . . . . . . . . . . . . . . . . 8 4.1. BR Tree Diagrams . . . . . . . . . . . . . . . . . . . . 8 4.2. Softwire BR Tree Diagram Descriptions . . . . . . . . . . 11 5. Softwire CE YANG Module . . . . . . . . . . . . . . . . . . . 12 6. BR Softwire YANG Module . . . . . . . . . . . . . . . . . . . 16 7. Common Softwire Element Groups YANG Module . . . . . . . . . 24 8. Security Considerations . . . . . . . . . . . . . . . . . . . 31 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 31 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 32 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 32 11.1. Normative References . . . . . . . . . . . . . . . . . . 32 11.2. Informative References . . . . . . . . . . . . . . . . . 33 Appendix A. Configuration Examples . . . . . . . . . . . . . . . 34 A.1. Configuration Example for a lw4o6 BR Binding-Table . . . 34 A.2. Configuration Example for a MAP-E BR . . . . . . . . . . 35 A.3. lw4o6 CE Configuration Example . . . . . . . . . . . . . 37 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 40 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 A+P softwire functional elements: Border Routers (BRs) and Customer Premises Sun, et al. Expires May 17, 2018 [Page 2] Internet-Draft YANG Module for A+P Softwires November 2017 Equipment (CEs). The softwire mechanisims covered in this document are Lightweight 4 over 6 [RFC7596], MAP-E [RFC7597], and MAP-T [RFC7599]. This document defines YANG data models [RFC6020] that can be used to configure and manage A+P softwire elements using the NETCONF protocol [RFC6241] for: Configuration Operational State Notifications 1.1. Terminology The reader should be familiar with the concepts and terms defined in [RFC7596], [RFC7597], [RFC7599], and the YANG data modelling language defined in [RFC6020] and [RFC7950]. The meaning of the symbols in tree diagrams is defined in [I-D.ietf-netmod-yang-tree-diagrams]. 2. Overview of the Models The document defines these two YANG data modules for the configuration and monitoring of softwire functional elements: ietf-softwire-ce Provides configuration and monititoring for softwire CE element. ietf-softwire-br Provides configuration and monititoring for softwire BR element. In addition, the following module is also defined: ietf-softwire-common Contains groups of functions that are common and are imported into the CE and BR modules. This approach has been taken so that the various modules can be easily extended to support additional softwire mechanisms, if required. The modules are defined as augments to the interface YANG module [RFC7223]. Within the BR and CE modules, the YANG "feature" statement is used to distinguish which of the different softwire mechanism(s) is relevant Sun, et al. Expires May 17, 2018 [Page 3] Internet-Draft YANG Module for A+P Softwires November 2017 for a specific element's configuraiton. For each module, a choice statement is included for either 'binding' or 'algorithmic'. Binding is used for configuring Lightweight 4over6, whereas Algorithmic is used for configuring MAP-T or MAP-E. In the 'algo-instances' container, a choice statement is included to specify MAP-E (encapsulation) or MAP-T (translation). The following table shows the how these choices are used to indicate the desired softwire mechanism: +--------------------+-----------+---------------+ | S46 Mechanism | ce-type? | data-plane? | +--------------------+-----------+---------------+ | Lightweight 4over6 | binding | n/a | | MAP-E | algorithm | encapsulation | | MAP-T | algorithm | translation | +--------------------+-----------+---------------+ Table 1: Softwire Mechanism Choice Statement Enumeration NETCONF notifications also included. Note: Earlier versions of this document combined the softwire mechanisms by their associated technologies rather than their function in the architecture. As the document was revised, it became apparent that dividing the modules by by their role in the architecture (CE or BR) was a better approach as this follows the intended function and existing implmemention approaches more closely. 2.1. Additional Configuration The softwire module only aims to provide configuration relevant for softwires. In order to fully specify a CE element, the following may also be necessary: o IPv6 routing configuration, to enable CE to obtain one or more IPv6 prefixes for softwire usage. YANG module for routing management is described in [RFC8022] o IPv4 routing configuration, to add one or more IPv4 destination prefix(es) reachable via the configured softwire. YANG module for routing management is described in [RFC8022] o Stateful NAT44 / NAPT management, to optionally specify a port set (PSID) along with its length. YANG module for NAT management is described in [I-D.ietf-opsawg-nat-yang] Note that Sun, et al. Expires May 17, 2018 [Page 4] Internet-Draft YANG Module for A+P Softwires November 2017 o Stateless NAT46 management, required by softwire translation based mechanisms (i.e. the assignment of a Network-Specific prefix to use for IPv4/IPv6 translation). YANG module for NAT management is described in [I-D.ietf-opsawg-nat-yang] As YANG modules for the configuration for these functions are already defined in other documents, they are not repeated, but imported here, as needed. Appendix A.3 provides XML examples of how these models can be used together. The CE must already have minimal IPv6 configuration in place so it is reachable by the Netconf client to obtain softwire configuration. If additional IPv6 specific configuration is necessary, the YANG modules defined in [RFC7277] and [RFC8022] may be used. 3. Softwire YANG CE Tree Diagram Figure 1 describes the softwire YANG module for CE elements. This module augments "ietf-interfaces", defined in [RFC7223] with an entry for the softwire. This entry can be referenced to configure IPv4 routing for the element. The module provides configuration and monitoring for all of the softwire mechanisms listed in Section 1. module: ietf-softwire-ce augment /if:interfaces/if:interface: +--rw softwire-payload-mtu? uint16 +--rw softwire-path-mru? uint16 +--rw (ce-type)? +--:(binding) {binding}? | +--rw binding-ipv6info? union | +--rw br-ipv6-addr inet:ipv6-address +--:(algorithm) {algorithm}? +--rw algo-instances +--rw algo-instance* [id] +--rw enable? boolean +--rw algo-versioning | +--rw version? uint64 | +--rw date? yang:date-and-time +--rw id uint32 +--rw name? string +--rw (data-plane)? | +--:(encapsulation) | | +--rw br-ipv6-addr inet:ipv6-address | +--:(translation) | +--rw dmr-ipv6-prefix? inet:ipv6-prefix +--rw ea-len uint8 Sun, et al. Expires May 17, 2018 [Page 5] Internet-Draft YANG Module for A+P Softwires November 2017 +--rw rule-ipv6-prefix inet:ipv6-prefix +--rw rule-ipv4-prefix inet:ipv4-prefix +--rw forwarding boolean augment /if:interfaces-state/if:interface: +--ro ce-interface +--ro name? string +--ro type? identityref +--ro sent-ipv4-packets? | yang:zero-based-counter64 +--ro sent-ipv4-bytes? | yang:zero-based-counter64 +--ro sent-ipv6-packets? | yang:zero-based-counter64 +--ro sent-ipv6-bytes? | yang:zero-based-counter64 +--ro rcvd-ipv4-packets? | yang:zero-based-counter64 +--ro rcvd-ipv4-bytes? | yang:zero-based-counter64 +--ro rcvd-ipv6-packets? | yang:zero-based-counter64 +--ro rcvd-ipv6-bytes? | yang:zero-based-counter64 +--ro dropped-ipv4-packets? | yang:zero-based-counter64 +--ro dropped-ipv4-bytes? | yang:zero-based-counter64 +--ro dropped-ipv6-packets? | yang:zero-based-counter64 +--ro dropped-ipv6-bytes? | yang:zero-based-counter64 +--ro dropped-ipv4-fragments? | yang:zero-based-counter64 +--ro dropped-ipv4-fragment-bytes? | yang:zero-based-counter64 +--ro ipv6-fragments-reassembled? | yang:zero-based-counter64 +--ro ipv6-fragments-bytes-reassembled? | yang:zero-based-counter64 +--ro out-icmpv4-error-packets? | yang:zero-based-counter64 +--ro out-icmpv6-error-packets? yang:zero-based-counter64 notifications: +---n softwire-ce-event {binding}? +--ro ce-binding-ipv6-addr-change inet:ipv6-address Sun, et al. Expires May 17, 2018 [Page 6] Internet-Draft YANG Module for A+P Softwires November 2017 Figure 1: Softwire YANG CE Tree Diagram 3.1. Softwire CE Tree Diagram Descriptions Additional information on some of the important CE elements is provided below: o softwire-payload-mtu: optionally used to set the IPv4 MTU for the softwire. Needed if the softwire implementation is unable to correctly calculate the correct IPv4 size automatically. o softwire-path-mru: optionally used to set the maximum IPv6 softwire packet size that can be received, including the encapsulation/translation overhead. Needed if the softwire implementation is unable to correctly calculate the correct IPv4 size automatically. o ce-type: provides a choice statement allowing the binding or algorithmic softwire mechanisms to be selected. Additional details relevant to binding softwire elements are: o binding-ipv6info: used to set the IPv6 address type which is combined in a binding entry, for a complete address or a prefix. o br-ipv6-addr: indicates the IPv6 of the remote BR. Additional details relevant to some of the important algorithmic elements are provided below: o algo-versioning: optionally used to add a incremental version number and/or timestamp to the algorithm. This can be used for logging/data retention purposes. The version number is incremented and a new timestamp value written whenever a change is made to the algorithm or a new instance is created. o forwarding: specifies whether the rule can be used as a Forward Mapping Rule (FMR). If not set, this rule is a Basic Mapping Rule (BMR) only and must not be used for forwarding. See Section 4.1 of [RFC7598]. o ea-len: used to set the length of the Embedded-Address (EA), which defined in the mapping rule for a MAP domain. o data-plane: provides a choice statement for either encapsulation (MAP-E) or translation (MAP-T). o br-ipv6-addr: defines the IPv6 address of the BR for MAP-E. Sun, et al. Expires May 17, 2018 [Page 7] Internet-Draft YANG Module for A+P Softwires November 2017 o dmr-ipv6-prefix: defines the Default Mapping Rule (DMR) IPv6 prefix of the BR for MAP-T. o stat-count (ro): use to show the numbers of packets and bytes information of specific element respectively. Additional information on the notification node is listed below: o ce-binding-ipv6-addr-change: if the CE's binding-ipv6-address changes for any reason, it SHOULD notify the NETCONF client. 4. Softwire BR YANG Tree Diagram 4.1. BR Tree Diagrams Figure 2 describes the high level softwire YANG module for BRs. The module provides configuration and monitoring for all of the softwire mechanisms listed in Section 1. module: ietf-softwire-br +--rw br-instances +--rw (br-type)? +--:(binding) {binding}? | +--rw binding {binding}? | +--rw br-instance* [id] | +--rw binding-table-versioning | | +--rw version? uint64 | | +--rw date? yang:date-and-time | +--rw id uint32 | +--rw name? string | +--rw softwire-num-threshold uint32 | +--rw softwires-payload-mtu uint16 | +--rw softwire-path-mru uint16 | +--rw enable-hairpinning? boolean | +--rw binding-table | | +--rw binding-entry* [binding-ipv6info] | | +--rw binding-ipv6info union | | +--rw binding-ipv4-addr? inet:ipv4-address | | +--rw port-set | | | +--rw psid-offset? uint8 | | | +--rw psid-len uint8 | | | +--rw psid uint16 | | +--rw br-ipv6-addr? inet:ipv6-address | +--rw icmp-policy | | +--rw icmpv4-errors | | | +--rw allow-incoming-icmpv4? boolean | | | +--rw generate-icmpv4-errors? boolean | | +--rw icmpv6-errors Sun, et al. Expires May 17, 2018 [Page 8] Internet-Draft YANG Module for A+P Softwires November 2017 | | +--rw generate-icmpv6-errors? boolean | | +--rw icmpv6-errors-rate? uint32 | +--ro traffic-stat | +--ro sent-ipv4-packets? | | yang:zero-based-counter64 | +--ro sent-ipv4-bytes? | | yang:zero-based-counter64 | +--ro sent-ipv6-packets? | | yang:zero-based-counter64 | +--ro sent-ipv6-bytes? | | yang:zero-based-counter64 | +--ro rcvd-ipv4-packets? | | yang:zero-based-counter64 | +--ro rcvd-ipv4-bytes? | | yang:zero-based-counter64 | +--ro rcvd-ipv6-packets? | | yang:zero-based-counter64 | +--ro rcvd-ipv6-bytes? | | yang:zero-based-counter64 | +--ro dropped-ipv4-packets? | | yang:zero-based-counter64 | +--ro dropped-ipv4-bytes? | | yang:zero-based-counter64 | +--ro dropped-ipv6-packets? | | yang:zero-based-counter64 | +--ro dropped-ipv6-bytes? | | yang:zero-based-counter64 | +--ro dropped-ipv4-fragments? | | yang:zero-based-counter64 | +--ro dropped-ipv4-fragment-bytes? | | yang:zero-based-counter64 | +--ro ipv6-fragments-reassembled? | | yang:zero-based-counter64 | +--ro ipv6-fragments-bytes-reassembled? | | yang:zero-based-counter64 | +--ro out-icmpv4-error-packets? | | yang:zero-based-counter64 | +--ro out-icmpv6-error-packets? | | yang:zero-based-counter64 | +--ro hairpin-ipv4-bytes? | | yang:zero-based-counter64 | +--ro hairpin-ipv4-packets? | | yang:zero-based-counter64 | +--ro active-softwire-num? uint32 +--:(algorithm) {algorithm}? +--rw algorithm {algorithm}? +--rw algo-instance* [id] +--rw id uint32 Sun, et al. Expires May 17, 2018 [Page 9] Internet-Draft YANG Module for A+P Softwires November 2017 +--rw name? string +--rw algo-instances | +--rw algo-instance* [id] | +--rw enable? boolean | +--rw algo-versioning | | +--rw version? uint64 | | +--rw date? yang:date-and-time | +--rw id uint32 | +--rw name? string | +--rw (data-plane)? | | +--:(encapsulation) | | | +--rw br-ipv6-addr | | | inet:ipv6-address | | +--:(translation) | | +--rw dmr-ipv6-prefix? inet:ipv6-prefix | +--rw ea-len uint8 | +--rw rule-ipv6-prefix inet:ipv6-prefix | +--rw rule-ipv4-prefix inet:ipv4-prefix | +--rw forwarding boolean | +--rw psid-offset? uint8 | +--rw psid-len uint8 | +--rw psid uint16 +--ro traffic-stat +--ro sent-ipv4-packets? | yang:zero-based-counter64 +--ro sent-ipv4-bytes? | yang:zero-based-counter64 +--ro sent-ipv6-packets? | yang:zero-based-counter64 +--ro sent-ipv6-bytes? | yang:zero-based-counter64 +--ro rcvd-ipv4-packets? | yang:zero-based-counter64 +--ro rcvd-ipv4-bytes? | yang:zero-based-counter64 +--ro rcvd-ipv6-packets? | yang:zero-based-counter64 +--ro rcvd-ipv6-bytes? | yang:zero-based-counter64 +--ro dropped-ipv4-packets? | yang:zero-based-counter64 +--ro dropped-ipv4-bytes? | yang:zero-based-counter64 +--ro dropped-ipv6-packets? | yang:zero-based-counter64 +--ro dropped-ipv6-bytes? | yang:zero-based-counter64 +--ro dropped-ipv4-fragments? Sun, et al. Expires May 17, 2018 [Page 10] Internet-Draft YANG Module for A+P Softwires November 2017 | yang:zero-based-counter64 +--ro dropped-ipv4-fragment-bytes? | yang:zero-based-counter64 +--ro ipv6-fragments-reassembled? | yang:zero-based-counter64 +--ro ipv6-fragments-bytes-reassembled? | yang:zero-based-counter64 +--ro out-icmpv4-error-packets? | yang:zero-based-counter64 +--ro out-icmpv6-error-packets? yang:zero-based-counter64 notifications: +---n softwire-br-event {binding}? | +--ro br-id? -> /br-instances/binding/br-instance/id | +--ro invalid-entry* leafref | +--ro added-entry* inet:ipv6-address | +--ro modified-entry* leafref +---n softwire-algorithm-instance-event {algorithm}? +--ro algo-id | -> /br-instances/algorithm/algo-instance/id +--ro invalid-entry-id* | -> /br-instances/algorithm/algo-instance/id +--ro added-entry* | -> /br-instances/algorithm/algo-instance/id +--ro modified-entry* -> /br-instances/algorithm/algo-instance/id Figure 2: Softwire YANG BR Tree 4.2. Softwire BR Tree Diagram Descriptions The descriptions for some of the leaves in the BR module are the same as in Figure 1. Information on the additional elements are provided below: o binding-table-versioning: optionally used to add an incremental version number and/or timestamp to the binding table. This can be used for logging/data retention purposes. The version number is incremented and a new timestamp value written whenever a change is made to the contents of the binding table or a new binding table list is created. o binding-entry: used to define the binding relationship between 3-tuples, which contains the lwB4's IPv6 address/prefix, the allocated IPv4 address and restricted port-set. For detail information, please refer to [RFC7596]. Sun, et al. Expires May 17, 2018 [Page 11] Internet-Draft YANG Module for A+P Softwires November 2017 o softwire-num-threshold: used to set the maximum number of softwires that can be created on the lw4o6 element simultaneously. o active-softwire-num (ro): used to present the number of softwires currently provisioned on the element. o active (ro): used to show the status of particular binding-entry. Additional information on some of the important notification nodes is listed below: o invalid-entry, added-entry, modified-entry: used to notify the client that a specific binding entry or MAP rule is expired or invalidated, added, or modified. 5. Softwire CE YANG Module This module imports typedefs from [RFC6991]. file "ietf-softwire-ce@2017-11-14.yang" module ietf-softwire-ce { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-softwire-ce"; prefix "softwire-ce"; import ietf-inet-types {prefix inet; } import ietf-interfaces {prefix if; } import iana-if-type {prefix ianaift; } import ietf-softwire-common {prefix softwire-common; } organization "Softwire Working Group"; contact " Qi Sun Hao Wang Yong Cui Ian Sladjana Zoric Mohamed Boucadair Rajiv "; description "This document defines a YANG data module for the configuration and management of A+P Softwire Customer Premises Equipment (CEs). It covers Lightweight 4over6, MAP-E, and MAP-T mechanisms. Sun, et al. Expires May 17, 2018 [Page 12] Internet-Draft YANG Module for A+P Softwires November 2017 Copyright (c) 2017 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 2017-11-14 { description "Initial revision."; reference "RFC XXXX: YANG Modules for IPv4-in-IPv6 Address plus Port Softwires"; } /* * Features */ feature binding { description "Binding is used for configuring Lightweight 4over6 mechanism. Binding softwire mechanisms are IPv4-over-IPv6 tunnelling transition mechanisms 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 Border Relay (BR) 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 "RFC7596, RFC7597 & RFC7599"; } feature algorithm { 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. MAP-T is an IPv6 transition mechanism for transporting IPv4 packets across an IPv6 network using IP translation. It leverages a double stateless NAT64 based solution as well as the stateless algorithmic address & transport layer port mapping algorithm Sun, et al. Expires May 17, 2018 [Page 13] Internet-Draft YANG Module for A+P Softwires November 2017 defined for MAP-E. This feature indicates the instance functions as a MAP-E or MAP-T instance."; reference "RFC7597 & RFC7599"; } // Binding Entry grouping binding-entry { description "The lwAFTR maintains an address binding table that contains the binding 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; } description "The IPv6 information for a binding entry. If this is type IPv6 prefix, it indicates that the IPv6 source address of the CE is constructed according to the description in RFC7596; if it is type IPv6 address, it means the CE uses any valid /128 address from a prefix assigned to the CE."; reference "RFC7596"; } leaf br-ipv6-addr { type inet:ipv6-address; mandatory true; description "The IPv6 address for lwaftr."; } } // configuration parameters for CE softwire interface augment "/if:interfaces/if:interface" { when "if:type = 'ianaift:tunnel'"; description "CE Softwire interface configuration"; Sun, et al. Expires May 17, 2018 [Page 14] Internet-Draft YANG Module for A+P Softwires November 2017 leaf softwire-payload-mtu { type uint16; units bytes; description "The payload MTU for the Softwire tunnel."; } leaf softwire-path-mru { type uint16; units bytes; description "The path MRU for the softwire (payload + encapsulation overhead)."; } choice ce-type { description "Sets the CE softwire mechanism"; case binding { if-feature binding; description "CE binding configuration"; uses binding-entry; } case algorithm { if-feature algorithm; description "CE algorithm configuration"; uses softwire-common:algorithm; } } } // operational state parameters for CE softwire binding interface augment "/if:interfaces-state/if:interface" { when "if:type = 'ianaift:tunnel'"; description "CE Softwire binding interface operational state"; container ce-interface { config false; description "Data nodes for the operational state of interfaces."; leaf name { type string; description "The name of the interface."; reference "RFC 2863: The Interfaces Group MIB - ifName"; Sun, et al. Expires May 17, 2018 [Page 15] Internet-Draft YANG Module for A+P Softwires November 2017 } leaf type { type identityref { base if:interface-type; } description "The type of the interface."; reference "RFC 2863: The Interfaces Group MIB - ifType"; } uses softwire-common:traffic-stat; } } /* * Notifications */ notification softwire-ce-event { if-feature binding; description "CE notification"; leaf ce-binding-ipv6-addr-change { type inet:ipv6-address; mandatory true; description "If the CE's binding-ipv6-address changes for any reason, it SHOULD notify the NETCONF client."; } } } 6. BR Softwire YANG Module This module imports typedefs from [RFC6991]. file "ietf-softwire-br@2017-11-14.yang" module ietf-softwire-br { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-softwire-br"; prefix "softwire-br"; import ietf-inet-types {prefix inet; } import ietf-yang-types {prefix yang; } import ietf-softwire-common {prefix softwire-common; } Sun, et al. Expires May 17, 2018 [Page 16] Internet-Draft YANG Module for A+P Softwires November 2017 organization "Softwire Working Group"; contact " Qi Sun Hao Wang Yong Cui Ian Sladjana Zoric Mohamed Boucadair Rajiv "; description "This document defines a YANG data module for the configuration and management of A+P Softwire Border Routers. It covers Lightweight 4over6, MAP-E, and MAP-T mechanisms. Copyright (c) 2017 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 2017-11-14 { description "Initial revision."; reference "RFC XXXX: YANG Modules for IPv4-in-IPv6 Address plus Port Softwires"; } /* * Features */ feature binding { description "Binding is used for configuring Lightweight 4over6 mechanism. Binding softwire mechanisms are IPv4-over-IPv6 tunnelling transition mechanisms 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 Border Relay (BR) and a hub-and-spoke forwarding architecture. In order to delegate the NAPT function and achieve IPv4 address sharing, port-restricted Sun, et al. Expires May 17, 2018 [Page 17] Internet-Draft YANG Module for A+P Softwires November 2017 IPv4 addresses needs to be allocated to CEs."; reference "RFC7596, RFC7597 & RFC7599"; } feature algorithm { 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. MAP-T is an IPv6 transition mechanism for transporting IPv4 packets across an IPv6 network using IP translation. It leverages double stateless NAT64 based solution as well as the stateless algorithmic address & transport layer port mapping algorithm defined for MAP-E. This feature indicates the instance functions as a MAP-E or MAP-T instance."; reference "RFC7597 & RFC7599"; } container br-instances { description "BR Instances"; choice br-type { description "Select binding or algorithmic BR functionality."; case binding { if-feature binding; container binding { if-feature binding; description "lw4over6 (binding table) configuration."; list br-instance { key "id"; description "A set of lwAFTRs to be configured."; container binding-table-versioning { description "binding table's version"; leaf version{ type uint64; Sun, et al. Expires May 17, 2018 [Page 18] Internet-Draft YANG Module for A+P Softwires November 2017 description "Incremental version number of the binding table"; } leaf date { type yang:date-and-time; description "Timestamp of the binding table"; } } leaf id { type uint32; mandatory true; 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 softwires that can be created on the lwAFTR."; } leaf softwires-payload-mtu { type uint16; units bytes; mandatory true; description "The payload MTU for Lightweight 4over6 softwire."; } leaf softwire-path-mru { type uint16; units bytes; mandatory true; description "The path MRU for Lightweight 4over6 softwire."; } leaf enable-hairpinning { type boolean; default true; description "Enables/disables support for locally forwarding (hairpinning) traffic between two CEs"; reference "RFC7596 Section 6.2"; } Sun, et al. Expires May 17, 2018 [Page 19] Internet-Draft YANG Module for A+P Softwires November 2017 container binding-table { description "binding table"; list binding-entry { key "binding-ipv6info"; description "binding entry"; uses softwire-common:binding-entry; } } container icmp-policy { description "The lwAFTR can be configured to process or drop incoming ICMP messages, and to generate outgoing ICMP error messages or not."; container icmpv4-errors { description "ICMPv4 error processing configuration"; leaf allow-incoming-icmpv4 { type boolean; default true; description "Whether to allow processing of incoming ICMPv4 packets."; reference "RFC7596"; } leaf generate-icmpv4-errors { type boolean; default true; description "Whether to generate outgoing ICMP error messages on receipt of an inbound IPv4 packet with no matching binding table entry."; reference "RFC7596 Seciton 5.2"; } } container icmpv6-errors { description "ICMPv6 error processing configuration"; leaf generate-icmpv6-errors { type boolean; default true; description "Whether to generate ICMPv6 errors messages if no matching binding table entry is found."; Sun, et al. Expires May 17, 2018 [Page 20] Internet-Draft YANG Module for A+P Softwires November 2017 reference "RFC7596 Section 6.2"; } leaf icmpv6-errors-rate { type uint32; description "Rate limit threshold in messages per-second for sending ICMPv6 errors messages"; reference "RFC7596 Section 9"; } } } container traffic-stat { config false; description "Traffic statistics information for the BR."; uses softwire-common:traffic-stat; leaf hairpin-ipv4-bytes { type yang:zero-based-counter64; description "IPv4 packets locally routed between two CEs (hairpinned)."; } leaf hairpin-ipv4-packets { type yang:zero-based-counter64; description "IPv4 bytes locally routed between two CEs (hairpinned)."; } leaf active-softwire-num { type uint32; config false; description "The number of currently active softwires on the lw4over6 (binding) instance."; } } } } } case algorithm { if-feature algorithm; container algorithm { if-feature algorithm; description Sun, et al. Expires May 17, 2018 [Page 21] Internet-Draft YANG Module for A+P Softwires November 2017 "Indicate the instances support the MAP-E and MAP-T function. The instances advertise the map-e/map-t feature through the capability exchange mechanism when a NETCONF session is established."; list algo-instance { key "id"; description "Instances of algorithm"; leaf id { type uint32; mandatory true; description "id"; } leaf name { type string; description "The MAP instance name."; } uses softwire-common:algorithm { augment "algo-instances/algo-instance"{ description "Augments the port-set group for the algorithm."; uses softwire-common:port-set; } } container traffic-stat { config false; description "Traffic statistics information for the BR."; uses softwire-common:traffic-stat; } } } } } } /* * Notifications */ notification softwire-br-event { if-feature binding; description "Notifications for BR."; leaf br-id { type leafref { path "/br-instances/binding/" + "br-instance/id"; } description "..."; Sun, et al. Expires May 17, 2018 [Page 22] Internet-Draft YANG Module for A+P Softwires November 2017 } leaf-list invalid-entry { type leafref { path "/br-instances/binding/" + "br-instance[id=current()/../br-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 "/br-instances/binding/" + "br-instance[id=current()/../br-id]/" + "binding-table/binding-entry/binding-ipv6info"; } description "..."; } } notification softwire-algorithm-instance-event { if-feature algorithm; description "Notifications for MAP-E or MAP-T."; leaf algo-id { type leafref { path "/br-instances/algorithm/algo-instance/id"; } mandatory true; description "MAP-E or MAP-T event."; } leaf-list invalid-entry-id { type leafref { path "/br-instances/algorithm/algo-instance/id"; } Sun, et al. Expires May 17, 2018 [Page 23] Internet-Draft YANG Module for A+P Softwires November 2017 description "Invalid entry event."; } leaf-list added-entry { type leafref { path "/br-instances/algorithm/algo-instance/id"; } description "Added entry."; } leaf-list modified-entry { type leafref { path "/br-instances/algorithm/algo-instance/id"; } description "Modified entry."; } } } 7. Common Softwire Element Groups YANG Module The following YANG module contains definitions that are used by both the softwire CE and softwire BR YANG modules. file "ietf-softwire-common@2017-11-14.yang" module ietf-softwire-common { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-softwire-common"; prefix "softwire-common"; import ietf-inet-types { prefix inet; } import ietf-yang-types { prefix yang; } organization "Softwire Working Group"; contact " Qi Sun Hao Wang Yong Cui Ian Sladjana Zoric Mohamed Boucadair Rajiv "; Sun, et al. Expires May 17, 2018 [Page 24] Internet-Draft YANG Module for A+P Softwires November 2017 description "This document defines a YANG data model for the configuration and management of A+P Softwire Customer Premises Equipment (CEs). It covers Lightweight 4over6, MAP-E and MAP-T mechanisms. Copyright (c) 2017 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 2017-11-14 { description "Initial revision."; reference "RFC XXXX: YANG Modules for IPv4-in-IPv6 Address plus Port Softwires"; } /* * Grouping */ grouping port-set { description "Indicates a set of ports. It may be a simple port range, or use the PSID algorithm to represent a range of transport layer ports which will be used by a NAPT."; leaf psid-offset { type uint8 { range 0..16; } description "The number of offset bits. In Lightweight 4over6, the default value is 0 for assigning one contiguous port range. In MAP-E/T, the default value is 6, which means the system ports (0-1023) are excluded by default and assigns port ranges distributed across the entire port space, depending on either psid-len or the number of contiguous ports."; } leaf psid-len { type uint8 { range 0..15; } Sun, et al. Expires May 17, 2018 [Page 25] Internet-Draft YANG Module for A+P Softwires November 2017 mandatory true; description "The length of PSID, representing the sharing ratio for an IPv4 address. This, along with ea-len, also helps to calculate the number of contiguous ports per port range"; } leaf psid { type uint16; mandatory true; description "Port Set Identifier (PSID) value, which identifies a set of ports algorithmically."; } } grouping binding-entry { description "The lwAFTR maintains an address binding table that contains the binding 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; } description "The IPv6 information for a binding entry. If this is an IPv6 prefix, it indicates that the IPv6 source address of the CE is constructed according to the description in RFC7596; if it is an IPv6 address, it means the CE uses any /128 address from the assigned CE prefix."; reference "RFC7596"; } leaf binding-ipv4-addr { type inet:ipv4-address; 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 Sun, et al. Expires May 17, 2018 [Page 26] Internet-Draft YANG Module for A+P Softwires November 2017 port range."; uses port-set { refine "psid-offset" { default "0"; } } } leaf br-ipv6-addr { type inet:ipv6-address; description "The IPv6 address for lwaftr."; } } grouping algorithm { description "Indicate the instances support the MAP-E and MAP-T function. The instances advertise the map-e feature through the capability exchange mechanism when a NETCONF session is established."; container algo-instances { description "A set of MAP-E or MAP-T instances to be configured, applying to BRs and CEs. A MAP-E/T instance defines a MAP domain comprising one or more MAP-CE and MAP-BR"; list algo-instance { key "id"; description "MAP forwarding rule instance for MAP-E/MAP-T"; leaf enable { type boolean; description "Enable/disable individual MAP-E or MAP-T rule."; } container algo-versioning { description "algorithm's version"; leaf version { type uint64; description "Incremental version number for the algorithm"; } leaf date { type yang:date-and-time; description "Timestamp to the algorithm"; } } leaf id { type uint32; mandatory true; description "Algorithm Instance ID"; Sun, et al. Expires May 17, 2018 [Page 27] Internet-Draft YANG Module for A+P Softwires November 2017 } leaf name { type string; description "The name for the instance."; } choice data-plane { description "Selects MAP-E (encapsulation) or MAP-T (translation)"; case encapsulation { description "encapsulation for MAP-E"; leaf br-ipv6-addr { type inet:ipv6-address; mandatory true; description "The IPv6 address of the MAP-E BR."; } } case translation { description "translation for MAP-T"; leaf dmr-ipv6-prefix { type inet:ipv6-prefix; description "The IPv6 prefix of the MAP-T BR. "; } } } 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 identifier. The length of the EA-bits is defined as part of a MAP rule for a MAP domain."; } 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."; } Sun, et al. Expires May 17, 2018 [Page 28] Internet-Draft YANG Module for A+P Softwires November 2017 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."; } } } } grouping traffic-stat { description "Traffic statistics"; leaf sent-ipv4-packets { type yang:zero-based-counter64; description "Number of decapsulated/translated IPv4 packets sent. "; } leaf sent-ipv4-bytes { type yang:zero-based-counter64; description "Decapsulated/translated IPv4 traffic sent, in bytes"; } leaf sent-ipv6-packets { type yang:zero-based-counter64; description "Number of encapsulated/translated IPv6 packets sent. "; } leaf sent-ipv6-bytes { type yang:zero-based-counter64; description "Encapsulated/translated IPv6 traffic sent, in bytes"; } leaf rcvd-ipv4-packets { type yang:zero-based-counter64; description "Number of IPv4 packets received for processing."; } leaf rcvd-ipv4-bytes { type yang:zero-based-counter64; description "IPv4 traffic received for processing, in bytes"; } leaf rcvd-ipv6-packets { type yang:zero-based-counter64; description "Number of IPv6 packets received for processing."; } leaf rcvd-ipv6-bytes { type yang:zero-based-counter64; description "IPv6 traffic received for processing, in bytes"; Sun, et al. Expires May 17, 2018 [Page 29] Internet-Draft YANG Module for A+P Softwires November 2017 } leaf dropped-ipv4-packets { type yang:zero-based-counter64; description "Number of IPv4 packets dropped."; } leaf dropped-ipv4-bytes { type yang:zero-based-counter64; description "IPv4traffic dropped, in bytes"; } leaf dropped-ipv6-packets { type yang:zero-based-counter64; description "Number of IPv4 packets dropped."; } leaf dropped-ipv6-bytes { type yang:zero-based-counter64; description "IPv4 traffic dropped, in bytes"; } leaf dropped-ipv4-fragments { type yang:zero-based-counter64; description "Number of fragmented IPv4 packets dropped"; } leaf dropped-ipv4-fragment-bytes { type yang:zero-based-counter64; description "Fragmented IPv4 traffic dropped, in bytes"; } leaf ipv6-fragments-reassembled { type yang:zero-based-counter64; description "Number of IPv6 fragments successfully reassembled"; } leaf ipv6-fragments-bytes-reassembled { type yang:zero-based-counter64; description "IPv6 fragments successfully reassembled, in bytes"; } leaf out-icmpv4-error-packets { type yang:zero-based-counter64; description "Internally generated ICMPv4 error packets."; } leaf out-icmpv6-error-packets { type yang:zero-based-counter64; description "Internally generted ICMPv6 error packets."; } } } Sun, et al. Expires May 17, 2018 [Page 30] Internet-Draft YANG Module for A+P Softwires November 2017 8. Security Considerations The YANG module defined in this document is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC5246]. The NETCONF access control model [RFC6536] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. All data nodes defined in the YANG modules which can be created, modified, and deleted (i.e., config true, which is the default) are considered sensitive. Write operations (e.g., edit-config) applied to these data nodes without proper protection can negatively affect network operations. 9. IANA Considerations This document requests IANA to register the following URIs in the "IETF XML Registry" [RFC3688]. URI: urn:ietf:params:xml:ns:yang:softwire-ce Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:softwire-br Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:softwire-common Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace. This document requests that IANA registers the following YANG modules in the "YANG Module Names" registry [RFC6020]. name: ietf-softwire-ce namespace: urn:ietf:params:xml:ns:yang:softwire-ce prefix: softwire-ce reference: RFC XXXX Sun, et al. Expires May 17, 2018 [Page 31] Internet-Draft YANG Module for A+P Softwires November 2017 name: ietf-softwire-br namespace: urn:ietf:params:xml:ns:yang:softwire-br prefix: softwire-br reference: RFC XXXX name: ietf-softwire-common namespace: urn:ietf:params:xml:ns:yang:softwire-common prefix: softwire-br reference: RFC XXXX 10. Acknowledgements The authors would like to thank Lishan Li, Bert Wijnen, Giles Heron, Ole Troan, and Leo Tietz for their contributions to this work. 11. References 11.1. 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, . [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, August 2008, . [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, . Sun, et al. Expires May 17, 2018 [Page 32] Internet-Draft YANG Module for A+P Softwires November 2017 [RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration Protocol (NETCONF) Access Control Model", RFC 6536, DOI 10.17487/RFC6536, March 2012, . [RFC7223] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 7223, DOI 10.17487/RFC7223, May 2014, . [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, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . 11.2. Informative References [I-D.ietf-netmod-yang-tree-diagrams] Bjorklund, M. and L. Berger, "YANG Tree Diagrams", draft- ietf-netmod-yang-tree-diagrams-02 (work in progress), October 2017. Sun, et al. Expires May 17, 2018 [Page 33] Internet-Draft YANG Module for A+P Softwires November 2017 [I-D.ietf-opsawg-nat-yang] Boucadair, M., Sivakumar, S., Jacquenet, C., Vinapamula, S., and Q. Wu, "A YANG Data Model for Network Address Translation (NAT) and Network Prefix Translation (NPT)", draft-ietf-opsawg-nat-yang-08 (work in progress), November 2017. [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . [RFC7277] Bjorklund, M., "A YANG Data Model for IP Management", RFC 7277, DOI 10.17487/RFC7277, June 2014, . [RFC8022] Lhotka, L. and A. Lindem, "A YANG Data Model for Routing Management", RFC 8022, DOI 10.17487/RFC8022, November 2016, . Appendix A. Configuration Examples The following sections of the document provide examples on how these YANG modules could be used for configuring softwire elements. A.1. Configuration Example for a lw4o6 BR 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 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. Consider an example for the following lw4o6 binding table entry: lwB4 Binding IPv6 Address: 2001:db8::1 lwB4 Binding IPv4 Address: 192.0.2.1 lwB4 IPv6 Address: 123 lwB4 PSID Length 8 Sun, et al. Expires May 17, 2018 [Page 34] Internet-Draft YANG Module for A+P Softwires November 2017 BR IPv6 Address: 2001:db8:1::2 1 2001:db8::1 192.0.2.1 123 8 2001:db8:1::2 1024 1540 1500 Figure 3: lw4o6 Binding-Table Configuration XML A.2. Configuration Example for a MAP-E BR A MAP-E BR is configured with forward mapping rules for the clients it is serving. In this example (taken from [RFC7597], Appendix A, Example 2), the following parameters are required: o Rule IPv6 Prefix o Rule IPv4 Prefix o Rule EA-bit bit length o IPv6 Address of MAP-BR The mapping rule has two functions: identifying the destination CE IPv6 address for encapsulating inbound IPv4 packets and the Sun, et al. Expires May 17, 2018 [Page 35] Internet-Draft YANG Module for A+P Softwires November 2017 validation of outbound IPv4-in-IPv6 packets received from the CE for de-capsulation. The transport type for the data plane also needs to be configured for encapsulation to enable MAP-E and forwarding needs to be enabled. Consider an example for the following MAP-E Forwarding Mapping Rule: Data plane: encapsulation Rule IPv6 Prefix: 2001:db8::/40 Rule IPv4 Prefix: 192.0.2.0/24 Rule EA-bit Length: 16 BR IPv6 Address: 2001:db8:ffff::1 Here is the example MAP-E BR configuration xml: 42 1234 encapsulation 16 192.0.2.0/24 2001:db8::/40 true 2001:db8:ffff::1 6 8 Figure 4: MAP-E FMR Configuration XML Sun, et al. Expires May 17, 2018 [Page 36] Internet-Draft YANG Module for A+P Softwires November 2017 A.3. lw4o6 CE Configuration Example The following section provides XML examples for configuring a lw4o6 CE. Examples for routing and NAT44 are also provided for convienience. Consider an example for the following lw4o6 CE Configuration: lwB4 Binding IPv6 Address: 2001:db8::1 lwB4 Binding IPv4 Address: 192.0.2.1 lwB4 IPv6 Address: 123 lwB4 PSID Length 8 BR IPv6 Address: 2001:db8:1::2 lw4o6-wan iana:tunnel 2001:db8:1::2 2001:db8::1 Figure 5: lw4o6 CE Configuration XML In the above example, the interface name is defined for the softwire tunnel. This name is then referenced by the routing configuration for the IPv4 route. The following section provides example configuration for the CE's IPv4 routing, using the YANG module described in [RFC8022]. Sun, et al. Expires May 17, 2018 [Page 37] Internet-Draft YANG Module for A+P Softwires November 2017 static v4 0.0.0.0/0 lw4o6-wan Figure 6: lw4o6 CE Routing Configuration XML The following section provides example configuration for the CE's NAPT44 function, using the YANG module described in [I-D.ietf-opsawg-nat-yang]. 1 1 1 192.0.2.1 6 8 52 1 Sun, et al. Expires May 17, 2018 [Page 38] Internet-Draft YANG Module for A+P Softwires November 2017 80 1 8 6 32 17 16 1 192.0.2.1/32 192.168.1.0/24 6 2 192.0.2.1/32 192.168.1.0/24 17 3 192.0.2.1/32 192.168.1.0/24 1 Figure 7: lw4o6 NAT Configuration XML Sun, et al. Expires May 17, 2018 [Page 39] Internet-Draft YANG Module for A+P Softwires November 2017 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 Sladjana Zechlin Deutsche Telekom AG Landgrabenweg 151 Bonn, NRW 53227 Germany Email: sladjana.zechlin@telekom.de Sun, et al. Expires May 17, 2018 [Page 40] Internet-Draft YANG Module for A+P Softwires November 2017 Mohamed Boucadair Orange Rennes 35000 France Email: mohamed.boucadair@orange.com Rajiv Asati Cisco Systems, Inc. 7025 Kit Creek Rd. RTP, NC 27709 USA Email: Rajiva@cisco.com Sun, et al. Expires May 17, 2018 [Page 41]