| Softwire Working Group | Q. Sun |
| Internet-Draft | H. Wang |
| Intended status: Standards Track | Y. Cui |
| Expires: May 18, 2018 | Tsinghua University |
| I. Farrer | |
| S. Zechlin | |
| Deutsche Telekom AG | |
| M. Boucadair | |
| Orange | |
| R. Asati | |
| Cisco Systems, Inc. | |
| November 14, 2017 |
YANG Modules for IPv4-in-IPv6 Address plus Port Softwires
draft-ietf-softwire-yang-03
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.
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].
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 18, 2018.
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.
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 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:
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].
The document defines these two YANG data modules for the configuration and monitoring of softwire functional elements:
In addition, the following module is also defined:
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 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 |
NETCONF notifications also included.
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:
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.
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
+--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
Figure 1: Softwire YANG CE Tree Diagram
Additional information on some of the important CE elements is provided below:
Additional details relevant to binding softwire elements are:
Additional details relevant to some of the important algorithmic elements are provided below:
Additional information on the notification node is listed below:
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
| | +--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
+--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?
| 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
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:
Additional information on some of the important notification nodes is listed below:
This module imports typedefs from [RFC6991].
<CODE BEGINS>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 <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>
Sladjana Zoric <sladjana.zoric@telekom.de>
Mohamed Boucadair <mohamed.boucadair@orange.com>
Rajiv <Asati rajiva@cisco.com>
";
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.
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
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";
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";
}
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.";
}
}
}
<CODE ENDS>
This module imports typedefs from [RFC6991].
<CODE BEGINS>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; }
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>
Sladjana Zoric <sladjana.zoric@telekom.de>
Mohamed Boucadair <mohamed.boucadair@orange.com>
Rajiv <Asati rajiva@cisco.com>
";
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
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;
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";
}
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.";
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
"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 "...";
}
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";
}
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.";
}
}
}
<CODE ENDS>
The following YANG module contains definitions that are used by both the softwire CE and softwire BR YANG modules.
<CODE BEGINS>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 <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>
Sladjana Zoric <sladjana.zoric@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 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;
}
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
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";
}
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.";
}
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";
}
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.";
}
}
}
<CODE ENDS>
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.
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 IANA to register the following URIs in the "IETF XML Registry" [RFC3688].
name: ietf-softwire-ce
namespace: urn:ietf:params:xml:ns:yang:softwire-ce
prefix: softwire-ce
reference: RFC XXXX
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
This document requests that IANA registers the following YANG modules in the "YANG Module Names" registry [RFC6020].
The authors would like to thank Lishan Li, Bert Wijnen, Giles Heron, Ole Troan, and Leo Tietz for their contributions to this work.
| [I-D.ietf-netmod-yang-tree-diagrams] | Bjorklund, M. and L. Berger, "YANG Tree Diagrams", Internet-Draft draft-ietf-netmod-yang-tree-diagrams-02, October 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)", Internet-Draft draft-ietf-opsawg-nat-yang-08, November 2017. |
| [RFC6991] | Schoenwaelder, J., "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. |
The following sections of the document provide examples on how these YANG modules could be used for configuring softwire elements.
The lwAFTR maintains an address binding table which contains the following 3-tuples:
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:
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<softwire-config xmlns="urn:ietf:params:xml:ns:yang:ietf-softwire-br">
<br-instances>
<binding>
<br-instance>
<id>1</id>
<binding-table>
<binding-entry>
<binding-ipv6info>2001:db8::1</binding-ipv6info>
<binding-ipv4-addr>192.0.2.1</binding-ipv4-addr>
<port-set>
<psid>123</psid>
<psid-len>8</psid-len>
</port-set>
<br-ipv6-addr>2001:db8:1::2</br-ipv6-addr>
</binding-entry>
</binding-table>
<softwire-num-threshold>1024</softwire-num-threshold>
<softwire-path-mru>1540</softwire-path-mru>
<softwire-payload-mtu>1500</softwire-payload-mtu>
</br-instance>
</binding>
</br-instances>
</softwire-config>
</config>
Figure 3: lw4o6 Binding-Table Configuration XML
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:
The mapping rule has two functions: identifying the destination CE IPv6 address for encapsulating inbound IPv4 packets and the 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:
Here is the example MAP-E BR configuration xml:
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<softwire-config xmlns="urn:ietf:params:xml:ns:yang:ietf-softwire-br">
<br-instances>
<algorithm>
<algo-instance>
<id>42</id>
<algo-instances>
<algo-instance>
<id>1234</id>
<data-plane>encapsulation</data-plane>
<ea-len>16</ea-len>
<rule-ipv4-prefix>192.0.2.0/24</rule-ipv4-prefix>
<rule-ipv6-prefix>2001:db8::/40</rule-ipv6-prefix>
<forwarding>true</forwarding>
<br-ipv6-addr>2001:db8:ffff::1</br-ipv6-addr>
<psid-offset>6</psid-offset>
<psid-len>8</psid-len>
</algo-instance>
</algo-instances>
</algo-instance>
</algorithm>
</br-instances>
</softwire-config>
</config>
Figure 4: MAP-E FMR Configuration XML
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:
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
<interface>
<name>lw4o6-wan</name>
<type
xmlns:iana="urn:ietf:params:xml:ns:yang:iana-if-type">
iana:tunnel
</type>
<ce-interface
xmlns="urn:ietf:params:xml:ns:yang:ietf-softwire-ce">
<br-ipv6-addr>2001:db8:1::2</br-ipv6-addr>
<binding-ipv6info>2001:db8::1</binding-ipv6info>
</ce-interface>
</interface>
</interfaces>
</config>
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].
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<routing xmlns="urn:ietf:params:xml:ns:yang:ietf-routing">
<control-plane-protocols>
<control-plane-protocol>
<type>static</type>
<name>v4</name>
<static-routes>
<ipv4
xmlns="urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing">
<route>
<destination-prefix>0.0.0.0/0</destination-prefix>
<next-hop>
<outgoing-interface>lw4o6-wan</outgoing-interface>
</next-hop>
</route>
</ipv4>
</static-routes>
</control-plane-protocol>
</control-plane-protocols>
</routing>
</config>
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].
<config xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
<nat xmlns="urn:ietf:params:xml:ns:yang:ietf-nat">
<instances>
<instance>
<id>1</id>
<policy>
<policy-id>1</policy-id>
<external-ip-address-pool>
<pool-id>1</pool-id>
<external-ip-pool>192.0.2.1</external-ip-pool>
</external-ip-address-pool>
<port-set-restrict>
<port-set-algo>
<psid-offset>6</psid-offset>
<psid-len>8</psid-len>
<psid>52</psid>
</port-set-algo>
</port-set-restrict>
<notify-pool-usage>
<pool-id>1</pool-id>
<high-threshold>80</high-threshold>
</notify-pool-usage>
</policy>
<mapping-limits>
<limit-per-protocol>
<protocol-id>1</protocol-id>
<limit>8</limit>
</limit-per-protocol>
<limit-per-protocol>
<protocol-id>6</protocol-id>
<limit>32</limit>
</limit-per-protocol>
<limit-per-protocol>
<protocol-id>17</protocol-id>
<limit>16</limit>
</limit-per-protocol>
</mapping-limits>
<mapping-table>
<mapping-entry>
<index>1</index>
<external-src-address>192.0.2.1/32</external-src-address>
<internal-src-address>192.168.1.0/24</internal-src-address>
<transport-protocol>6</transport-protocol>
</mapping-entry>
<mapping-entry>
<index>2</index>
<external-src-address>192.0.2.1/32</external-src-address>
<internal-src-address>192.168.1.0/24</internal-src-address>
<transport-protocol>17</transport-protocol>
</mapping-entry>
<mapping-entry>
<index>3</index>
<external-src-address>192.0.2.1/32</external-src-address>
<internal-src-address>192.168.1.0/24</internal-src-address>
<transport-protocol>1</transport-protocol>
</mapping-entry>
</mapping-table>
</instance>
</instances>
</nat>
</config>
Figure 7: lw4o6 NAT Configuration XML