Softwire Working Group Q. Sun
Internet-Draft H. Wang
Intended status: Standards Track Y. Cui
Expires: February 15, 2017 Tsinghua University
I. Farrer
S. Zoric
Deutsche Telekom AG
M. Boucadair
Orange
R. Asati
Cisco Systems, Inc.
August 14, 2016
A YANG Data Model for IPv4-in-IPv6 Softwires
draft-ietf-softwire-yang-00
Abstract
This document defines a YANG data model for the configuration and
operations (state, notification, RPC etc.) of IPv4-in-IPv6 Softwire
Border Routers 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 http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on February 15, 2017.
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Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Tree Diagrams . . . . . . . . . . . . . . . . . . . . . . 3
1.3. YANG Modelling of NAT44 Functionality . . . . . . . . . . 4
2. Common . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Lightweight 4over6 . . . . . . . . . . . . . . . . . . . . . 4
4. MAP-E and MAP-T . . . . . . . . . . . . . . . . . . . . . . . 4
5. Softwire YANG Tree Diagrams . . . . . . . . . . . . . . . . . 4
5.1. Common Tree Diagrams . . . . . . . . . . . . . . . . . . 4
5.2. Lightweight 4over6 Tree Diagrams . . . . . . . . . . . . 5
5.3. MAP-E and MAP-T Tree Diagrams . . . . . . . . . . . . . . 8
5.4. Notifications for Softwire YANG . . . . . . . . . . . . . 9
6. Softwire YANG Model . . . . . . . . . . . . . . . . . . . . . 10
7. Example of Configure lw4o6 Binding-Table . . . . . . . . . . 26
8. Security Considerations . . . . . . . . . . . . . . . . . . . 27
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 28
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 28
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 28
11.1. Normative References . . . . . . . . . . . . . . . . . . 28
11.2. Informative References . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 30
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
Equipment (CEs).
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This document defines a YANG data model [RFC6020] that can be used to
configure and manage A+P Softwire elements using the NETCONF protocol
[RFC6241]. DS-Lite YANG data model is defined in
[I-D.ietf-softwire-dslite-yang].
The Softwire YANG model is structured into two sub-models:
o Lightweight 4over6 [RFC7596]
o MAP-E [RFC7597] and MAP-T [RFC7599] (combined due to their common
configuration parameters).
Two root containers are defined:
1. Container "softwire-config" holds the collection of YANG
definitions common to all Softwire element configuration.
2. Container "softwire-state" holds YANG definitions for the
operational state of the Softwire elements.
A NETCONF notify module is also included.
This approach has been taken so that the model can be easily extended
to support additional Softwire mechanisms, if required.
1.1. Terminology
The reader should be familiar with the concepts and terms defined in
[RFC7596], [RFC7597], [RFC7599], and the YANG data modelling language
[RFC6020].
1.2. Tree Diagrams
The meaning of the symbols in these diagrams are as follows:
o Brackets "[" and "]" enclose list keys.
o Braces "{" and "}" enclose feature content.
o Parentheses "(" and ")" enclose choice and case nodes, and case
nodes are also marked with a colon (":").
o Symbols after data node names: "?" means an optional node, and "*"
denotes a list and leaf-list.
o Abbreviations before data node names: "rw" means configuration
data (read-write), and "ro" means state data (read-only).
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1.3. YANG Modelling of NAT44 Functionality
The model does not include CPE NAT-specific provisioning parameters
that may be used for IPv4 address sharing other than the external IP
address and port set which a softwire client may use for NAT44. NAT-
specific considerations are out of scope of this document. A YANG
model for the configuration and management of NAT gateways is
described in [I-D.sivakumar-yang-nat].
2. Common
The following sections of the document are structured with the root
of the Softwire YANG model (common to all mechanisms) described
first. Subsequent sections describe the models relevant to the
different softwire mechanisms. All functions are listed, but the
YANG models use the "feature" statement to distinguish among the
different softwire mechanisms. This document defines a new module
named "ietf-softwire" for Softwire data models such that this module
auments "ietf-ipv6-unicast-routing" module that is defined in
[I-D.ietf-netmod-routing-cfg].
3. Lightweight 4over6
Lightweight 4over6 (binding) includes two elements: lwAFTR (BR) and
lwB4 (CE). The lwAFTR holds configuration for IPv4-IPv6 address
bindings which are used for the forwarding of traffic originating
from lwB4s.
The lwB4 is configured with the relevant parameters for establishing
the IPv4-in-IPv6 tunnel including an IPv6 address for the lwAFTR and
the IPv4 configuration for NAT44.
4. MAP-E and MAP-T
MAP-E and MAP-T elements are provisioned with the MAP rules necessary
for defining MAP domains and forwarding rules. For MAP-T CEs, an
additional "ipv6-prefix" parameter is also included. Note that when
referring to MAP-E/T (algorithm), the CE and BR shares the same model
for configuration and management.
5. Softwire YANG Tree Diagrams
5.1. Common Tree Diagrams
Figure 1 describes the high level softwire YANG data model and the
way tree is organized is common to all of the different softwire
mechanisms listed in Section 1:
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+--rw softwire-config
| +--rw description? string
| +--rw binding {binding}?
| | +--rw br {br}?
| | +--rw cr {cr}?
| +--rw algorithm {algorithm}?
|
+--ro softwire-state
+--ro description? string
+--ro binding {binding}?
| +--ro br {br}?
| +--ro ce {ce}?
+--ro algorithm {algorithm}?
Figure 1: High Level Softwire YANG Tree Organization
5.2. Lightweight 4over6 Tree Diagrams
Figure 2 defines the softwire data model for lw4o6 (softwire binding
mode) which includes lwAFTR (BR) and lwB4 (CE):
module: ietf-softwire
+--rw softwire-config
| +--...
| +--rw binding {binding}?
| +--rw br {br}?
| | +--rw enable? boolean
| | +--rw br-instances
| | +--rw br-instance* [id]
| | +--rw binding-table-versioning
| | | +--rw binding-table-version? uint64
| | | +--rw binding-table-date? yang:date-and-time
| | +--rw id uint32
| | +--rw name? string
| | +--rw softwire-num-threshold uint32
| | +--rw tunnel-payload-mtu uint16
| | +--rw tunnel-path-mru uint16
| | +--rw binding-table
| | +--rw binding-entry* [binding-ipv6info]
| | +--rw binding-ipv6info union
| | +--rw binding-ipv4-addr inet:ipv4-address
| | +--rw port-set
| | | +--rw psid-offset uint8
| | | +--rw psid-len uint8
| | | +--rw psid uint16
| | +--rw br-ipv6-addr inet:ipv6-address
| | +--rw lifetime? uint32
| +--rw ce {ce}?
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| +--rw enable? boolean
| +--rw ce-instances
| +--rw ce-instance* [binding-ipv6info]
| +--rw name? string
| +--rw tunnel-payload-mtu uint16
| +--rw tunnel-path-mru uint16
| +--rw b4-ipv6-addr-format boolean
| +--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 lifetime? uint32
+--ro softwire-state
+--...
+--ro binding {binding}?
+--ro br {br}?
| +--ro br-instances
| +--ro br-instance* [id]
| +--ro id uint32
| +--ro name? string
| +--ro sentPacket? yang:zero-based-counter64
| +--ro sentByte? yang:zero-based-counter64
| +--ro rcvdPacket? yang:zero-based-counter64
| +--ro rcvdByte? yang:zero-based-counter64
| +--ro droppedPacket? yang:zero-based-counter64
| +--ro droppedByte? yang:zero-based-counter64
| +--ro active-softwire-num? uint32
| +--ro binding-table
| +--ro binding-entry* [binding-ipv6info]
| +--ro binding-ipv6info union
| +--ro active? boolean
+--ro ce {ce}?
+--ro ce-instances
+--ro ce-instance* [binding-ipv6info]
+--ro name? string
+--ro binding-ipv6info union
+--ro sentPacket? yang:zero-based-counter64
+--ro sentByte? yang:zero-based-counter64
+--ro rcvdPacket? yang:zero-based-counter64
+--ro rcvdByte? yang:zero-based-counter64
+--ro droppedPacket? yang:zero-based-counter64
+--ro droppedByte? yang:zero-based-counter64
Figure 2: Softwire Lightweight 4over6 Data Model Tree Structure
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The data model assumes that each CE/BR instance can: be enable/
disabled, be provisioned with a dedicated configuration data, and
maintain its own binding table.
Additional information on some of the important lwAFTR nodes is
provided below:
o binding-table-versioning: optionally used to add a 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].
o tunnel-payload-mtu: used to set the IPv4 MTU for the lw4o6 tunnel.
o tunnel-path-mru: used to set the maximum lw4o6 IPv6 encapsulating
packet size that can be received.
o psid-offset: used to set the number of offset bits.
o psid-len: defines the number of ports that will be allocated for
the softwire.
o psid: used to identify the set of ports allocated for a specific
softwire.
o tunnel-num-threshold: used to set the maximum number of tunnels
that can be created on the lw4o6 device simultaneously.
o active-tunnel-num (ro): used to present the number of tunnels
currently provisioned on the device.
o active (ro): used to show the status of particular binding-entry.
Additional information on some of the important lwB4 nodes is
provided below:
o b4-ipv6-addr-format: indicates the format of lwB4 IPv6 address.
If set to true, it indicates that the IPv6 source address of the
lwB4 is constructed according to the description in Section 6 of
[RFC7597]; if set to false, the lwB4 can use any /128 address from
the assigned IPv6 prefix.
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o binding-ipv6info: used to set the IPv6 address type which is
combined in a binding entry, for a complete address or a prefix.
5.3. MAP-E and MAP-T Tree Diagrams
Figure 3 defines the softwire data model for MAP-E and MAP-T:
module: ietf-softwire
+--rw softwire-config
| +--...
| +--rw algorithm {algorithm}?
| +--rw enable? boolean
| +--rw algorithm
| +--rw algo-instance* [id]
| +--rw algo-versioning
| | +--rw algo-version? uint64
| | +--rw algo-date? yang:date-and-time
| +--rw id uint32
| +--rw name? string
| +--rw data-plane enumeration
| +--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 tunnel-payload-mtu uint16
| +--rw tunnel-path-mru uint16
| +--rw br-ipv6-addr inet:ipv6-address
| +--rw dmr-ipv6-addr inet:ipv6-prefix
+--ro softwire-state
+--...
+--ro algorithm {algorithm}?
+--ro algo-instances
+--ro algo-instance* [id]
+--ro id int32
+--ro name? string
+--ro sentPacket? yang:zero-based-counter64
+--ro sentByte? yang:zero-based-counter64
+--ro rcvdPacket? yang:zero-based-counter64
+--ro rcvdByte? yang:zero-based-counter64
+--ro droppedPacket? yang:zero-based-counter64
+--ro droppedByte? yang:zero-based-counter64
Figure 3: Softwire MAP-E and MAP-T Data Model Structure
Additional information on some of the important MAP-E and MAP-T nodes
is provided below:
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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 dmr-ipv6-prefix: defines the Default Mapping Rule (DMR) for MAP-T.
This parameter is optional when configuring a MAP-T BR.
o stat-count (ro): use to show the numbers of packets and bytes
information of specific device respectively.
5.4. Notifications for Softwire YANG
This section describes the tree structure for notifications. These
notifications pertain to the configuration and monitoring portions of
the specific Softwire mechanisms. The logic is that the softwire
instance notifies the NETCONF client with the index for a mapping
entry and the NETCONF client retrieves the related information from
the operational datastore of that instance.
module: ietf-softwire
notifications:
+---n softwire-binding-br-event {binding,br}?
| +--ro br-id? -> /softwire-state/binding/br/.../id
| +--ro invalid-entry* -> /softwire-config/binding/br/.../binding-table/binding-entry/binding-ipv6info
| +--ro added-entry* inet:ipv6-address
| +--ro modified-entry* -> /softwire-config/binding/br/.../binding-table/binding-entry/binding-ipv6info
+---n softwire-binding-ce-event {binding,ce}?
| +--ro ce-binding-ipv6-addr-change inet:ipv6-address
+---n softwire-algorithm-instance-event {algorithm}?
+--ro algo-id -> /softwire-config/algorithm/.../id
+--ro invalid-entry* -> /softwire-config/algorithm/.../id
+--ro added-entry* -> /softwire-config/algorithm/.../id
+--ro modified-entry* -> /softwire-config/algorithm/.../id
Figure 4: Softwire Notifications Data Model Structure
Additional information on some of the important notification nodes is
listed below:
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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.
o ce-binding-ipv6-addr-change: used to notify that the lwB4's
binding-ipv6-address has been changed or the value of the
'b4-ipv6-addr-format' is "False".
6. Softwire YANG Model
This module imports typedefs from [RFC6991].
<CODE BEGINS> file "ietf-softwire@2016-06-04.yang"
module ietf-softwire {
namespace "urn:ietf:params:xml:ns:yang:ietf-softwire";
prefix "softwire";
import ietf-inet-types {prefix inet; }
import ietf-yang-types {prefix yang; }
organization "Softwire Working Group";
contact
"
Qi Sun <sunqi.ietf@gmail.com>
Hao Wang <wangh13@mails.tsinghua.edu.cn>
Yong Cui <yong@csnet1.cs.tsinghua.edu.cn>
Ian <Farrer ian.farrer@telekom.de>
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 Border Routers (BRs) and Customer
Premises Equipment (CEs). It covers Lightweight 4over6,
MAP-E and MAP-T mechanisms.
Copyright (c) 2016 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 2016-06-04 {
description
"Version-05: Combined MAP-E/MAP-T into a single tree. Added binding
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table/alogorthm versioning";
reference "-05";
}
revision 2015-09-30 {
description
"Version-04: Fix YANG syntax; Add flags to map-rule; Remove
the map-rule-type element. ";
reference "-04";
}
revision 2015-04-07 {
description
"Version-03: Integrate lw4over6; Updata state nodes; Correct
grammar errors; Reuse groupings; Update descriptions.
Simplify the model.";
reference "-03";
}
revision 2015-02-10 {
description
"Version-02: Add notifications.";
reference "-02";
}
revision 2015-02-06 {
description
"Version-01: Correct grammar errors; Reuse groupings; Update
descriptions.";
reference "-01";
}
revision 2015-02-02 {
description
"Initial revision.";
reference "-00";
}
/*
* Features
*/
feature binding {
description
"Lightweight 4over6 (binding) is an IPv4-over-IPv6 tunnelling
transition mechanism. Lightweight 4over6 is a solution designed
specifically for complete independence between IPv6 subnet
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prefix (and /128 IPv6 address) and IPv4 address with or
without IPv4 address sharing.
This is accomplished by maintaining state for
each softwire (per-subscriber state) in the central lwAFTR and
a hub-and-spoke forwarding architecture. In order to delegate
the NAPT function and achieve IPv4 address sharing,
port-restricted IPv4 addresses needs to be allocated to CEs.
Besides lw4o6, this feature also covers MAP in 1:1 mode
(offset=0, PSID explicit)";
reference
"RFC7596";
}
feature br {
if-feature binding;
description
"The AFTR for Lightweight 4over6, so-called lwAFTR (BR). This
feature indicates that a instance functions as a lwAFTR (BR).
A lwAFTR (BR) is an IPv4-in-IPv6 tunnel concentrator that
maintains per-subscriber IPv4-IPv6 address binding.";
}
feature ce {
if-feature binding;
description
"The B4 for Lightweight 4over6, so-called lwB4 (CE). This
feature indicates that a instance functions as a lwB4 (CE). A
lwB4 (ce) is an IPv4-in-IPv6 tunnel initiator. It is
dual-stack capable node, either a directly connected end-host
or a CE. It sources IPv4 connections using the configured
port-set and the public IPv4 address.";
}
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.
The Mapping of Address and Port - Translation (MAP-T)
architecture is a double stateless NAT64 based solution. It uses
the stateless algorithmic address & transport layer port mapping
scheme defined in MAP-E. The MAP-T solution differs from MAP-E in
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the use of IPv4-IPv6 translation, rather than encapsulation, as
the form of IPv6 domain transport.
This feature indicates the instance functions as a MAP-E or
MAP-T instance.";
reference
"RFC7597 & RFC7599";
}
/*
* Grouping
*/
grouping port-set {
description
"Use the PSID algorithm to represent a range of transport layer
ports.";
leaf psid-offset {
type uint8 {
range 0..16;
}
mandatory true;
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 excludes system ports by default
and assigns distributed port ranges. If the this parameter is
larger than 0, the value of offset MUST be greater than 0.";
}
leaf psid-len {
type uint8 {
range 0..15;
}
mandatory true;
description
"The length of PSID, representing the sharing ratio for an
IPv4 address.";
}
leaf psid {
type uint16;
mandatory true;
description
"Port Set Identifier (PSID) value, which identifies a set
of ports algorithmically.";
}
}
grouping binding-entry {
description
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"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;
}
mandatory true;
description
"The IPv6 information for a binding entry.
If it's an IPv6 prefix, it indicates that
the IPv6 source address of the lwB4 is constructed
according to the description in RFC7596;
if it's an IPv6 address, it means the lwB4 uses
any /128 address from the assigned IPv6 prefix.
";
}
leaf binding-ipv4-addr {
type inet:ipv4-address;
mandatory true;
description
"The IPv4 address assigned to the lwB4, which is
used as the IPv4 external address
for lwB4 local NAPT44.";
}
container port-set {
description
"For Lightweight 4over6, the default value
of offset should be 0, to configure one contiguous
port range.";
uses port-set {
refine psid-offset {
default "0";
}
}
}
leaf br-ipv6-addr {
type inet:ipv6-address;
mandatory true;
description
"The IPv6 address for lwaftr.";
}
leaf lifetime {
type uint32;
units seconds;
description "The lifetime for the binding entry";
}
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}
/*
grouping nat-table {
description
"Grouping 'nat-table' is not extended. The current mechanism
is focusing on the provisioning of external IP address and
port set; other NAT-specific considerations are out of scope.";
}
*/
grouping traffic-stat {
description "Traffic statistics";
leaf sentPacket {
type yang:zero-based-counter64;
description "Number of packets sent.";
}
leaf sentByte {
type yang:zero-based-counter64;
description "Traffic sent, in bytes";
}
leaf rcvdPacket {
type yang:zero-based-counter64;
description "Number of packets received.";
}
leaf rcvdByte {
type yang:zero-based-counter64;
description "Traffic received, in bytes";
}
leaf droppedPacket {
type yang:zero-based-counter64;
description "Number of packets dropped.";
}
leaf droppedByte {
type yang:zero-based-counter64;
description "Traffic dropped, in bytes";
}
}
/*
* Configuration Data Nodes
*/
container softwire-config {
description
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"The configuration data for Softwire instances. And the shared
data describes the softwire data model which is common to all of
the different softwire mechanisms, such as description.";
leaf description {
type string;
description
"A textual description of Softwire.";
}
container binding {
if-feature binding;
description
"lw4over6 (binding) configuration.";
container br {
if-feature br;
description
"Indicate this instance supports the lwAFTR (BR) function.
The instances advertise the BR feature through the
capability exchange mechanism when a NETCONF session is
established.";
leaf enable {
type boolean;
description
"Enable/disable the lwAFTR (BR) function.";
}
container br-instances {
description
"A set of BRs to be configured.";
list br-instance {
key "id";
description
"A set of lwAFTRs to be configured.";
container binding-table-version {
description "binding table's version";
leaf binding-table-version{
type uint64;
description "Incremental version number
to the binding table";
}
leaf binding-table-date {
type yang:date-and-time;
description "Timestamp to the binding
table";
}
}
leaf id {
type uint32;
mandatory true;
description "An instance identifier.";
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}
leaf name {
type string;
description "The name for the lwaftr.";
}
leaf softwire-num-threshold {
type uint32;
mandatory true;
description
"The maximum number of tunnels that can be created on
the lwAFTR.";
}
leaf tunnel-payload-mtu {
type uint16;
mandatory true;
description
"The payload MTU for Lightweight 4over6 tunnel.";
}
leaf tunnel-path-mru {
type uint16;
mandatory true;
description
"The path MRU for Lightweight 4over6 tunnel.";
}
container binding-table {
description "binding table";
list binding-entry {
key "binding-ipv6info";
description "binding entry";
uses binding-entry;
}
}
}
}
}
container ce {
if-feature ce;
description
"Indicate this instance supports the lwB4 (CE) function.
The instances advertise the CE feature through the
capability exchange mechanism when a NETCONF session is
established.";
leaf enable {
type boolean;
description
"Enable/disable the lwB4 (CE) function.";
}
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container ce-instances {
description
"A set of CEs to be configured.";
list ce-instance {
key "binding-ipv6info";
description "instances for CE";
leaf name {
type string;
description "The CE's name.";
}
leaf tunnel-payload-mtu {
type uint16;
mandatory true;
description
"The payload MTU for Lightweight 4over6 tunnel.";
}
leaf tunnel-path-mru {
type uint16;
mandatory true;
description
"The path MRU for Lightweight 4over6 tunnel.";
}
leaf b4-ipv6-addr-format {
type boolean;
mandatory true;
description
"The format of lwB4 (CE) IPv6 address. If set to true,
it indicates that the IPv6 source address of the lwB4
is constructed according to the description in
[RFC7596]; if set to false, the lwB4 (CE)
can use any /128 address from the assigned IPv6
prefix.";
}
uses binding-entry;
}
}
}
}
container algorithm {
if-feature 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.";
leaf enable {
type boolean;
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description
"Enable/disable the MAP-E or MAP-T function.";
}
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 "instance for MAP-E/MAP-T";
container algo-versioning {
description "algorithm's version";
leaf algo-version {
type uint64;
description "Incremental version number to
the algorithm";
}
leaf algo-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.";
}
leaf data-plane {
type enumeration {
enum "encapsulation" {
description "encapsulation for MAP-E";
}
enum "translation" {
description "translation for MAP-T";
}
}
description
"Encapsulation is for MAP-E while translation is
for MAP-T";
}
leaf ea-len {
type uint8;
mandatory true;
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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.";
}
leaf psid-offset {
type uint8 {
range 0..16;
}
mandatory true;
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 excludes system ports by default
and assigns distributed port ranges. If the this parameter is
larger than 0, the value of offset MUST be greater than 0.";
}
leaf psid-len {
type uint8 {
range 0..15;
}
mandatory true;
description
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"The length of PSID, representing the sharing ratio for an
IPv4 address.";
}
leaf tunnel-payload-mtu {
type uint16;
description
"The payload MTU for MAP-E tunnel.";
}
leaf tunnel-path-mru {
type uint16;
description
"The path MRU for MAP-E tunnel.";
}
leaf br-ipv6-addr {
type inet:ipv6-address;
mandatory true;
description
"The IPv6 address of the MAP-E BR.";
}
leaf dmr-ipv6-prefix {
type inet:ipv6-prefix;
description
"The IPv6 prefix of the MAP-T BR. ";
}
}
}
}
}
/*
* Operational state Data Nodes
*/
container softwire-state {
config false;
description
"The operational state data for Softwire instances. ";
leaf description {
type string;
description
"A textual description of the softwire instances.";
}
container binding {
if-feature binding;
description
"lw4over6 (binding) state.";
container br {
if-feature br;
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config false;
description
"Indicate this instance supports the lwAFTR (BR) function.
The instances advertise the lwaftr (BR) feature through the
capability exchange mechanism when a NETCONF session is
established.";
container br-instances {
description
"A set of BRs.";
list br-instance {
key "id";
description "instances for BR";
leaf id {
type uint32;
mandatory true;
description "id";
}
leaf name {
type string;
description "The name for this lwaftr.";
}
uses traffic-stat;
leaf active-softwire-num {
type uint32;
description
"The number of currently active tunnels on the
lw4over6 (binding) instance.";
}
container binding-table {
description "id";
list binding-entry {
key "binding-ipv6info";
description "An identifier of the binding entry.";
leaf binding-ipv6info {
type union {
type inet:ipv6-address;
type inet:ipv6-prefix;
}
mandatory true;
description
"The IPv6 information used to identify
a binding entry. ";
}
leaf active {
type boolean;
description
"Status of a specific tunnel.";
}
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}
}
}
}
}
container ce {
if-feature ce;
config false;
description
"Indicate this instance supports the lwB4 (CE) function.
The instances advertise the lwb4 (CE) feature through the
capability exchange mechanism when a NETCONF session is
established.";
container ce-instances {
description
"Status of the configured CEs.";
list ce-instance {
key "binding-ipv6info";
description "a lwB4 (CE) instance.";
leaf name {
type string;
description "The CE's name.";
}
leaf binding-ipv6info {
type union {
type inet:ipv6-address;
type inet:ipv6-prefix;
}
mandatory true;
description
"The IPv6 information used to identify
a binding entry. ";
}
uses traffic-stat;
}
}
}
}
container algorithm {
if-feature algorithm;
config false;
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
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established.";
container algo-instances {
description
"Status of MAP-E instance(s).";
list algo-instance {
key "id";
description "Instances for algorithm";
leaf id {
type uint32;
mandatory true;
description "id";
}
leaf name {
type string;
description "The map-e instance name.";
}
uses traffic-stat;
}
}
}
}
/*
* Notifications
*/
notification softwire-br-event {
if-feature binding;
if-feature br;
description "Notification for BR.";
leaf br-id {
type leafref {
path
"/softwire-state/binding/br/br-instances/"
+ "br-instance/id";
}
description "...";
}
leaf-list invalid-entry {
type leafref {
path
"/softwire-config/binding/br/br-instances/"
+ "br-instance[id=current()/../br-id]/"
+ "binding-table/binding-entry/binding-ipv6info";
}
description
"Notify the client that a specific binding entry has been
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expired/invalid. The binding-ipv6info identifies an entry.";
}
leaf-list added-entry {
type inet:ipv6-address;
description
"Notify the client that a binding entry has been added.
The ipv6 address of that entry is the index. The client
get other information from the lwaftr about the entry
indexed by that ipv6 address.
";
}
leaf-list modified-entry {
type leafref {
path
"/softwire-config/binding/br/br-instances/"
+ "br-instance[id=current()/../br-id]/"
+ "binding-table/binding-entry/binding-ipv6info";
}
description "...";
}
}
notification softwire-ce-event {
if-feature binding;
if-feature ce;
description "CE notification";
leaf ce-binding-ipv6-addr-change {
type inet:ipv6-address;
mandatory true;
description
"The source tunnel IPv6 address of the lwB4.
If 'b4-ipv6-addr-format' is false, or the lwb4's
binding-ipv6-address changes for any reason,
it SHOULD notify the NETCONF client.";
}
}
notification softwire-algorithm-instance-event {
if-feature algorithm;
description "Notifications for MAP-E or MAP-T.";
leaf algo-id {
type leafref {
path
"/softwire-config/algorithm/algo-instances/algo-instance/id";
}
mandatory true;
description "MAP-E or MAP-T event.";
}
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leaf-list invalid-entry-id {
type leafref {
path
"/softwire-config/algorithm/algo-instances/algo-instance/id";
}
description "Invalid entry event.";
}
leaf-list added-entry {
type leafref {
path
"/softwire-config/algorithm/algo-instances/algo-instance/id";
}
description "Added entry.";
}
leaf-list modified-entry {
type leafref {
path
"/softwire-config/algorithm/algo-instances/algo-instance/id";
}
description "Modified entry.";
}
}
}
<CODE ENDS>
7. Example of Configure lw4o6 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.
Let's consider an example to add an entry that maintains the
relationship between 3-tuples of lwB4 (2001:db8::1), '192.0.2.1' and
'1234' in the binding table of the lwAFTR (2001:db8::2). Here is the
example binding-table configuration xml:
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<rpc message-id="101"
xmlns:nc="urn:params:xml:ns:yang:ietf-softwire:1.0">
<!-- replace with IANA namespace when assigned. -->
<edit-config>
<target>
<running/>
</target>
<softwire-config>
<lw4o6-aftr>
<lw4o6-aftr-instances>
<lw4o6-aftr-instance>
<aftr-ipv6-addr>2001:db8::2</aftr-ipv6-addr>
<binding-table>
<binding-entry>
<binding-ipv4-addr>192.0.2.1</binding-ipv4-addr>
<port-set>
<psid>1234</psid>
</port-set>
<binding-ipv6-addr>2001:db8::1</binding-ipv6-addr>
<active>1</active>
</binding-entry>
</binding-table>
</lw4o6-aftr-instance>
</lw4o6-aftr-instances>
</lw4o6-aftr>
</softwire-config>
Figure 5: lw4o6 Binding-Table Configuration XML
8. Security Considerations
The YANG module defined in this memo is designed to be accessed via
the NETCONF protocol [RFC6241]. The lowest NETCONF layer is the
secure transport layer and the mandatory to implement secure
transport is SSH [RFC6242]. The NETCONF access control model
[RFC6536] provides the means to restrict access for particular
NETCONF users to a pre-configured subset of all available NETCONF
protocol operations and content.
All data nodes defined in the YANG module which can be created,
modified and deleted (i.e., config true, which is the default).
These data nodes are considered sensitive. Write operations (e.g.,
edit-config) applied to these data nodes without proper protection
can negatively affect network operations.
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9. IANA Considerations
This document requests IANA to register the following URI in the
"IETF XML Registry" [RFC3688].
URI: urn:ietf:params:xml:ns:yang:softwire
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.
This document requests IANA to register the following YANG module in
the "YANG Module Names" registry [RFC6020].
name: ietf-dslite-aftr
namespace: urn:ietf:params:xml:ns:yang:softwire
prefix: softwire
reference: RFC XXXX
10. Acknowledgements
The authors would like to thank Lishan Li, Bert Wijnen, Giles Heron,
and Ole Troan 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,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<http://www.rfc-editor.org/info/rfc3688>.
[RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for
the Network Configuration Protocol (NETCONF)", RFC 6020,
DOI 10.17487/RFC6020, October 2010,
<http://www.rfc-editor.org/info/rfc6020>.
[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,
<http://www.rfc-editor.org/info/rfc6241>.
[RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure
Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
<http://www.rfc-editor.org/info/rfc6242>.
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[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration
Protocol (NETCONF) Access Control Model", RFC 6536,
DOI 10.17487/RFC6536, March 2012,
<http://www.rfc-editor.org/info/rfc6536>.
[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, <http://www.rfc-editor.org/info/rfc7596>.
[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,
<http://www.rfc-editor.org/info/rfc7597>.
[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,
<http://www.rfc-editor.org/info/rfc7598>.
[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, <http://www.rfc-editor.org/info/rfc7599>.
11.2. Informative References
[I-D.ietf-netmod-routing-cfg]
Lhotka, L. and A. Lindem, "A YANG Data Model for Routing
Management", draft-ietf-netmod-routing-cfg-22 (work in
progress), July 2016.
[I-D.ietf-softwire-dslite-yang]
Boucadair, M., Jacquenet, C., and S. Sivakumar, "A YANG
Data Model for the DS-Lite Address Family Transition
Router (AFTR)", draft-ietf-softwire-dslite-yang-00 (work
in progress), August 2016.
[I-D.sivakumar-yang-nat]
Sivakumar, S., Boucadair, M., and S. <>, "YANG Data Model
for Network Address Translation (NAT)", draft-sivakumar-
yang-nat-04 (work in progress), March 2016.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<http://www.rfc-editor.org/info/rfc6991>.
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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 Zoric
Deutsche Telekom AG
CTO-IPT,Landgrabenweg 151
Bonn, NRW 53227
Germany
Email: sladjana.zoric@telekom.de
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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
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