YANG Modules for
IPv4-in-IPv6 Address plus Port SoftwiresTsinghua UniversityBeijing100084P.R. China+86-10-6260-3059yong@csnet1.cs.tsinghua.edu.cnDeutsche Telekom AGCTO-ATI,Landgrabenweg 151BonnNRW53227Germanyian.farrer@telekom.deOrangeRennes35000Francemohamed.boucadair@orange.comTsinghua UniversityBeijing100084P.R. China+86-10-6278-5822sunqi.ietf@gmail.comTsinghua UniversityBeijing100084P.R. China+86-10-6278-5822lh.sunlinh@gmail.comDeutsche Telekom AGLandgrabenweg 151BonnNRW53227Germanysladjana.zechlin@telekom.deCisco Systems, Inc.7025 Kit Creek Rd.RTPNC27709USARajiva@cisco.comSoftwire Working GroupThis document defines YANG modules for the configuration and
operation of IPv4-in-IPv6 softwire Border Relays and Customer Premises
Equipment for the Lightweight 4over6, Mapping of Address and Port with
Encapsulation (MAP-E), and Mapping of Address and Port using Translation
(MAP-T) softwire mechanisms.Please update these statements within this document with the RFC
number to be assigned to this document:"This version of this YANG module is part of RFC XXXX;""RFC XXXX: YANG Modules for IPv4-in-IPv6 Address plus Port
Softwires";"reference: RFC XXXX"Please update the "revision" date of the YANG module.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 address plus
port (A+P) softwire functional elements: Border Routers (BRs) and
Customer Premises Equipment (CEs, a.k.a., CPE). The softwire mechanisms
covered in this document are Lightweight 4 over 6 (lw4o6) , Mapping of Address and Port with Encapsulation
(MAP-E) , and Mapping of Address and Port
using Translation (MAP-T) .This document focuses on A+P mechanisms; the reader can refer to
for a YANG module
for DS-Lite .This document defines YANG modules
that can be used to configure and manage A+P softwire elements using the
NETCONF protocol for:ConfigurationOperational StateNotificationsThe reader should be familiar with the concepts and terms defined in
, , , and the YANG data modelling language defined
in .The adopts the Network Management Datastore Architecture (NMDA) . The meaning of the symbols in tree diagrams is
defined in .The document uses BR to refer to MAP BR or Lightweight 4over6 BR .For simplicity, "algorithm" is used to refer to "mapping algorithm"
.A network element may support one or multiple instances of a softwire
mechanism; each of these instances (i.e., binding instances, MAP-E
instances, or MAP-T instances) may have its own configuration and
parameters. The term 'algo-instance' is used to denote both MAP-E and
MAP-T instances. This document specifies the initial version of an IANA-maintained
module (iana-tunnel-type) to identify a collection of tunnel types
assigned by IANA () . Moreover, the document defines the following two YANG modules for
the configuration and monitoring of softwire functional elements:Provides configuration and
monitoring for softwire CE element. This module is defined as
augments to the interface YANG module .Provides configuration and
monitoring for softwire BR element.In addition, the following module is defined:Contains groups of common
functions that 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.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 configuration. For each module, a
choice statement 'ce-type' is included for either 'binding' or
'algorithm'. 'Binding' is used for configuring Lightweight 4over6,
whereas 'algorithm' is used for configuring MAP-T or MAP-E.In the 'algo-instances' container, a choice statement 'data-plane'
is included to specify MAP-E (encapsulation) or MAP-T (translation).
shows how these
choices are used to indicate the desired softwire mechanism:S46 Mechanismce-type?data-plane?Lightweight 4over6bindingn/aMAP-EalgorithmencapsulationMAP-TalgorithmtranslationNETCONF notifications are also included.Note: Earlier versions of this specification 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 their role in the
architecture (CE or BR) was a better approach as this follows the
intended function and existing implementation approaches more
closely.The softwire modules only aim to provide configuration relevant for
softwires. In order to fully provision a CE element, the following may
also be necessary:IPv6 forwarding and routing configuration, to enable CE to
obtain one or more IPv6 prefixes for softwire usage. A YANG module
for routing management is described in .IPv4 routing configuration, to add one or more IPv4 destination
prefix(es) reachable via the configured softwire. A YANG module
for routing management is described in .Stateful NAT44/NAPT management, to optionally specify a port
set (Port Set Identifier (PSID)) along with its length. A YANG
module for NAT management is described in .Stateless NAT46 management, required by softwire translation
based mechanisms (i.e., the assignment of a Network-Specific
Prefix to use for IPv4/IPv6 translation). A YANG module for NAT
management is described in .As YANG modules for the above functions are already defined in
other documents, their functionality is not duplicated here and they
should be referred to, as needed. provides XML examples of how these
modules 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 and may be used.The CE module provides configuration and monitoring for all of the
softwire mechanisms covered in this document (i.e., Lightweight
4over6, MAP-E, and MAP-T).This module augments "ietf-interfaces", defined in with an entry for the softwire. This entry
can be referenced to configure IPv4 forwarding features for the
element. This entry is added only if tunnel type () is set to 'aplusp'. shows the tree structure of
the softwire CE YANG module:Additional information related to the operation of a CE element is
provided below: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 Maximum Transit Unit (MTU)
size automatically.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
Maximum Receive Unit (MRU) size automatically .ce-type: provides a choice statement allowing the binding or
algorithmic softwire mechanisms to be selected.Further details relevant to binding softwire elements are:binding-ipv6info: used to set the IPv6 binding prefix type to
identify which IPv6 address to use as the tunnel source. It can be
'ipv6-prefix' or 'ipv6-address'.br-ipv6-addr: sets the IPv6 address of the remote BR.Additional details relevant to some of the important algorithmic
elements are provided below:algo-versioning: optionally used to associate a version number
and/or timestamp to the algorithm. This can be used for
logging/data retention purposes .
The version number is selected to uniquely identify the algorithm
configuration and a new value written whenever a change is made to
the algorithm or a new algo-instance is created.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. Refer to Section
4.1 of .ea-len: used to set the length of the Embedded-Address (EA),
which is defined in the mapping rule for a MAP domain.data-plane: provides a choice statement for either
encapsulation (MAP-E) or translation (MAP-T).br-ipv6-addr: defines the IPv6 address of the BR. This
information is valid for MAP-E.dmr-ipv6-prefix: defines the Default Mapping Rule (DMR) IPv6
prefix of the BR. This information is valid for MAP-T.Additional information on the notification node is listed
below:ce-binding-ipv6-addr-change: if the CE's binding IPv6 address
changes for any reason, the NETCONF client will be notified.The BR YANG module provides configuration and monitoring for all of
the softwire mechanisms covered in this document (i.e., Lightweight
4over6, MAP-E, and MAP-T). provides the tree structure of
this module: /br-instances/binding/bind-instance/name
| +--ro invalid-entry* leafref
| +--ro added-entry* inet:ipv6-address
| +--ro modified-entry* leafref
+---n softwire-algorithm-instance-event {map-e, map-t}?
+--ro algo-name
| -> /br-instances/algorithm/algo-instance/name
+--ro invalid-entry-id*
| -> /br-instances/algorithm/algo-instance/name
+--ro added-entry*
| -> /br-instances/algorithm/algo-instance/name
+--ro modified-entry*
-> /br-instances/algorithm/algo-instance/name
]]>The descriptions for leaves which are common with the CE module are
provided in . Descriptions
for additional elements are provided below:binding-table-versioning: optionally used to associate a
version number and/or timestamp to the binding table. This can be
used for logging or data retention purposes . The version number is selected to
uniquely identify the binding table configuration 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.binding-entry: used to define the binding relationship between
3-tuples {lwB4's IPv6 address/prefix, the allocated IPv4 address,
restricted port-set}. For detail information, please refer to
.softwire-num-max: used to set the maximum number of softwire
binding rules that can be created on the lw4o6 element
simultaneously. This paramter must not be set to zero because this
is equivalent to disabling the BR instance.active-softwire-num: holds the number of softwires currently
provisioned on the BR element.Additional information on some of the important notification nodes
is listed below:invalid-entry, added-entry, modified-entry: used to notify the
NETCONF client that a specific binding entry or MAP rule has
expired, been invalidated, added, or modified.The iana-tunnel-type module imports the module defined in . file "iana-tunnel-type@2018-10-23.yang"
module iana-tunnel-type {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:iana-tunnel-type";
prefix iana-tunnel-type;
import iana-if-type {
prefix ift;
reference
"RFC 7224: IANA Interface Type YANG Module";
}
organization
"IANA";
contact
"Internet Assigned Numbers Authority
Postal: ICANN
12025 Waterfront Drive, Suite 300
Los Angeles, CA 90094-2536
United States of America
Tel: +1 310 301 5800
";
description
"This module contains a collection of YANG data types defined
by IANA and used for tunnel types.
Copyright (c) 2018 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision 2018-10-23 {
description
"Initial revision.";
reference
"RFC XXXX: YANG Modules for IPv4-in-IPv6 Address plus Port
Softwires";
}
identity other {
base ift:tunnel;
description
"None of the following values.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity direct {
base ift:tunnel;
description
"No intermediate header.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity gre {
base ift:tunnel;
description
"GRE encapsulation.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity minimal {
base ift:tunnel;
description
"Minimal encapsulation.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity l2tp {
base ift:tunnel;
description
"L2TP encapsulation.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity pptp {
base ift:tunnel;
description
"PPTP encapsulation.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity l2f {
base ift:tunnel;
description
"L2F encapsulation.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity udp {
base ift:tunnel;
description
"UDP encapsulation.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity atmp {
base ift:tunnel;
description
"ATMP encapsulation.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity msdp {
base ift:tunnel;
description
"MSDP encapsulation.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity sixtofour {
base ift:tunnel;
description
"6to4 encapsulation.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity sixoverfour {
base ift:tunnel;
description
"6over4 encapsulation.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity isatap {
base ift:tunnel;
description
"ISATAP encapsulation.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity teredo {
base ift:tunnel;
description
"Teredo encapsulation.";
reference
"RFC 4087: IP Tunnel MIB";
}
identity iphttps {
base ift:tunnel;
description
"IP over HTTPS (IP-HTTPS) Tunneling Protocol.";
}
identity softwiremesh {
base ift:tunnel;
description
"softwire mesh tunnel.";
reference
"RFC 7856: Softwire Mesh Management Information Base (MIB)";
}
identity dslite {
base ift:tunnel;
description
"DS-Lite tunnel.";
reference
"RFC 7870: Dual-Stack Lite (DS-Lite) Management Information
Base (MIB) for Address Family Transition Routers
(AFTRs)";
}
identity aplusp {
base ift:tunnel;
description
"A+P encapsulation.";
reference
"RFC XXXX: YANG Modules for IPv4-in-IPv6 Address plus Port
Softwires";
}
}
]]>This module imports the modules defined in , , and . It also imports the 'ietf-softwire-common'
module.file "ietf-softwire-ce@2018-10-23.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;
reference "Section 4 of RFC 6991";
}
import ietf-interfaces {
prefix if;
reference "RFC 8343: A YANG Data Model for Interface Management";
}
import ietf-softwire-common {
prefix softwire-common;
reference
"RFC XXXX: YANG Modules for IPv4-in-IPv6 Address plus Port
Softwires";
}
import iana-tunnel-type {
prefix iana-tunnel-type;
reference
"RFC XXXX: YANG Modules for IPv4-in-IPv6 Address plus Port
Softwires";
}
organization
"IETF Softwire Working Group";
contact
"WG Web:
WG List:
Author: Qi Sun
Author: Linhui Sun
Author: Yong Cui
Author: Ian Farrer
Author: Sladjana Zoric
Author: Mohamed Boucadair
Author: Rajiv Asati
";
description
"This document defines a YANG 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) 2018 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision 2018-10-23 {
description
"Initial revision.";
reference
"RFC XXXX: YANG Modules for IPv4-in-IPv6 Address plus Port
Softwires";
}
/*
* Features
*/
feature binding-mode {
description
"Binding is used for configuring the Lightweight 4over6 mechanism.
Binding based softwire mechanisms are IPv4-over-IPv6 tunnelling
transition mechanisms specifically intended for complete
independence between the IPv6 subnet prefix (and 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 using
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.
This feature indicates that the network element can function as
one or more binding based softwire instances.";
reference
"RFC7596: Lightweight 4over6: An Extension to the Dual-Stack Lite
Architecture
RFC7597: Mapping of Address and Port with Encapsulation (MAP-E)
RFC7599: Mapping of Address and Port using Translation (MAP-T)";
}
feature map-e {
description
"MAP-E is an IPv6 transition mechanism for transporting IPv4
packets across an IPv6 network using IP encapsulation. MAP-E
allows for a reduction of the amount of centralized state using
rules to express IPv4/IPv6 address mappings. This introduces an
algorithmic relationship between the IPv6 subnet and IPv4
address.
This feature indicates that the network element can function as
one or more MAP-E softwire instances.";
reference
"RFC7597: Mapping of Address and Port with Encapsulation (MAP-E)";
}
feature map-t {
description
"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 that the network element can function as
one or more MAP-T softwire instances.";
reference
"RFC7599: Mapping of Address and Port using Translation (MAP-T)";
}
// Binding Entry
grouping binding-entry {
description
"The binding BR (Border Relay) maintains an address binding table
that contains the binding between the CE'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.
When the IPv6 prefix type is used,
the IPv6 source address of the CE is constructed
according to the description in RFC7596.
If the IPv6 address type is used, the CE can use
any valid /128 address from a prefix assigned to
the CE.";
reference "Section 5.1 of RFC7596.";
}
leaf br-ipv6-addr {
type inet:ipv6-address;
mandatory true;
description
"The IPv6 address of the binding BR.";
}
}
// configuration and stateful parameters for softwire CE interface
augment "/if:interfaces/if:interface" {
when "derived-from(if:type, 'iana-tunnel-type:aplusp')";
description
"Softwire CE interface configuration";
leaf softwire-payload-mtu {
type uint16;
units "bytes";
description
"The payload IPv4 MTU for the softwire tunnel.";
}
leaf softwire-path-mru {
type uint16;
units "bytes";
description
"The path MRU for the softwire (payload + encapsulation
overhead).";
reference
"RFC 4213: Basic Transition Mechanisms for IPv6 Hosts and
Routers";
}
choice ce-type {
description
"Sets the softwire CE mechanism";
case binding {
if-feature "binding-mode";
description
"CE binding configuration";
uses binding-entry;
}
case algo {
if-feature "map-e or map-t";
description
"CE algorithm configuration";
container algo-instances {
description
"Collection of MAP-E/MAP-T parameters";
list algo-instance {
key "name";
description
"MAP forwarding rule instance for
MAP-E/MAP-T";
leaf name {
type string;
mandatory true;
description
"The name is used to uniquely identify an algorithm
instance.
This name can be automatically assigned
or explicitly configured.";
}
uses softwire-common:algorithm-instance;
}
}
}
}
}
augment "/if:interfaces/if:interface/if:statistics" {
when "derived-from(../if:type, 'iana-tunnel-type:aplusp')";
description
"Softwire CE interface statistics.";
uses softwire-common:traffic-stat;
}
/*
* Notifications
*/
notification softwire-ce-event {
if-feature "binding-mode";
description
"CE notification";
leaf ce-binding-ipv6-addr-change {
type inet:ipv6-address;
mandatory true;
description
"This notification is generated whenever the CE's binding IPv6
address changes for any reason.";
}
}
}
]]>This module imports typedefs from . It
also imports the 'ietf-softwire-common' module.file "ietf-softwire-br@2018-10-23.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;
reference "Section 4 of RFC 6991";
}
import ietf-yang-types {
prefix yang;
reference "Section 3 of RFC 6991";
}
import ietf-softwire-common {
prefix softwire-common;
reference
"RFC XXXX: YANG Modules for IPv4-in-IPv6 Address plus Port
Softwires";
}
organization
"IETF Softwire Working Group";
contact
"WG Web:
WG List:
Author: Qi Sun
Author: Linhui Sun
Author: Yong Cui
Author: Ian Farrer
Author: Sladjana Zoric
Author: Mohamed Boucadair
Author: Rajiv Asati
";
description
"This document defines a YANG module for the configuration and
management of A+P Softwire Border Routers. It covers Lightweight
4over6, MAP-E, and MAP-T mechanisms.
Copyright (c) 2018 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision 2018-10-23 {
description
"Initial revision.";
reference
"RFC XXXX: YANG Modules for IPv4-in-IPv6 Address plus Port
Softwires";
}
/*
* Groupings
*/
grouping port-set {
description
"Describes a set of layer 4 port numbers.
This may be a simple port range, or use the Port Set
Identifier (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 the assigned port ranges are 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, can
be used 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 binding BR maintains an address binding table that
contains the binding between the CE'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 CE binding entry.
When the IPv6 prefix type is used,
the IPv6 source address of the CE is constructed
according to the description in RFC7596;
if the IPv6 address type is used, the CE can use
any valid /128 address from a prefix assigned to
the CE.";
reference
"RFC7596: Lightweight 4over6: An Extension to the Dual-Stack
Lite Architecture";
}
leaf binding-ipv4-addr {
type inet:ipv4-address;
description
"The IPv4 address assigned to the binding CE,
which is used as the IPv4 external address
for binding CE local NAPT44.";
}
container port-set {
description
"For Lightweight 4over6, the default value
for 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 binding BR.";
}
}
/*
* Features
*/
feature binding-mode {
description
"Binding is used for configuring the Lightweight 4over6 mechanism.
Binding based softwire mechanisms are IPv4-over-IPv6 tunnelling
transition mechanisms specifically intended for complete
independence between the IPv6 subnet prefix (and 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 using
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.
This feature indicates that the network element can function as
one or more binding based softwire instances.";
reference
"RFC7596: Lightweight 4over6: An Extension to the Dual-Stack Lite
Architecture
RFC7597: Mapping of Address and Port with Encapsulation (MAP-E)
RFC7599: Mapping of Address and Port using Translation (MAP-T)";
}
feature map-e {
description
"MAP-E is an IPv6 transition mechanism for transporting IPv4
packets across an IPv6 network using IP encapsulation. MAP-E
allows for a reduction of the amount of centralized state using
rules to express IPv4/IPv6 address mappings. This introduces an
algorithmic relationship between the IPv6 subnet and IPv4
address.
This feature indicates that the network element can function as
one or more MAP-E softwire instances.";
reference
"RFC7597: Mapping of Address and Port with Encapsulation (MAP-E)";
}
feature map-t {
description
"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 that the network element can function as
one or more MAP-T softwire instances.";
reference
"RFC7599: Mapping of Address and Port using Translation (MAP-T)";
}
container br-instances {
description
"BR instances enabled in a network element.";
choice br-type {
description
"Select binding or algorithmic BR functionality.";
case binding {
if-feature "binding-mode";
container binding {
description
"binding mechanism (binding table) configuration.";
list bind-instance {
key "name";
description
"A set of binding instances to be configured.";
leaf name {
type string;
mandatory true;
description
"The name for the binding BR. It is used to uniquely
distinguish a binding instance by its name.";
}
leaf id {
type uint32;
description
"A binding instance identifier.
This identifier can be automatically assigned
or explicitly configured.";
}
container binding-table-versioning {
description
"binding table's version";
leaf version {
type uint64;
description
"Timestamp when the binding table was activated.
A binding instance may be provided with binding
entries that may change in time (e.g., increase
the size of the port set). When an abuse party
presents an external IP address/port, the version
of the binding table is important because, depending
on the version, a distinct customer may be
identified.
The timestamp is used as a key to find the
appropriate binding table that was put into effect
when an abuse occurred. ";
}
leaf date {
type yang:date-and-time;
description
"Timestamp of the binding table";
reference
"RFC7422: Deterministic Address Mapping to Reduce
Logging in Carrier-Grade NAT Deployments";
}
}
leaf softwire-num-max {
type uint32;
must ". >= 1";
mandatory true;
description
"The maximum number of softwires that can be created
on the binding BR.";
}
leaf softwire-payload-mtu {
type uint16;
units "bytes";
mandatory true;
description
"The payload IPv4 MTU for binding softwire.";
}
leaf softwire-path-mru {
type uint16;
units "bytes";
mandatory true;
description
"The path MRU for binding softwire.";
reference
"RFC4213: Basic Transition Mechanisms for IPv6 Hosts
and Routers";
}
leaf enable-hairpinning {
type boolean;
default "true";
description
"Enables/disables support for locally forwarding
(hairpinning) traffic between two CEs.";
reference "Section 6.2 of RFC7596";
}
container binding-table {
description
"binding table";
list binding-entry {
key "binding-ipv6info";
description
"binding entry";
uses binding-entry;
}
}
container icmp-policy {
description
"The binding BR can be configured to process or drop
incoming ICMP messages, and to generate outgoing ICMP
error messages.";
container icmpv4-errors {
description
"ICMPv4 error processing configuration";
leaf allow-incoming-icmpv4 {
type boolean;
default "true";
description
"Enables the processing of incoming ICMPv4
packets.";
reference
"RFC7596: Lightweight 4over6: An Extension to
the Dual-Stack Lite Architecture";
}
leaf icmpv4-rate {
type uint32;
description
"Rate limit threshold in messages per-second
for processing incoming ICMPv4 errors messages";
}
leaf generate-icmpv4-errors {
type boolean;
default "true";
description
"Enables the generation of outgoing ICMPv4 error
messages on receipt of an inbound IPv4 packet
with no matching binding table entry.";
reference "Seciton 5.2 of RFC7596.";
}
}
container icmpv6-errors {
description
"ICMPv6 error processing configuration";
leaf generate-icmpv6-errors {
type boolean;
default "true";
description
"Enables the generation of ICMPv6 error messages if
no matching binding table entry is found for a
received packet.";
reference "Section 6.2 of RFC7596.";
}
leaf icmpv6-rate {
type uint32;
description
"Rate limit threshold in messages per-second
for sending ICMPv6 errors messages";
reference "Section 9 of RFC7596.";
}
}
}
container traffic-stat {
config false;
description
"Traffic statistics information for the BR.";
leaf discontinuity-time {
type yang:date-and-time;
mandatory true;
description
"The time of the most recent occasion on which the BR
instance suffered a discontinuity. This must be
initialized when the BR instance is configured
or rebooted.";
}
uses softwire-common:traffic-stat;
leaf dropped-icmpv4-packets {
type yang:zero-based-counter64;
description
"ICMPv4 packets that are dropped as a result
of the ICMP policy. Typically, this can be any
incoming ICMPv4 packets if ICMPv4 processing is
disabled or incoming ICMPv4 packets that exceed
the ICMPv4 rate-limit threshold.
Discontinuities in the value of this counter can
occur at re-initialization of the management
system, and at other times as indicated by
the value of 'discontinuity-time'.";
}
leaf dropped-icmpv4-bytes {
type yang:zero-based-counter64;
description
"ICMPv4 messages, in bytes, that are dropped as
a result of the ICMP policy. Typically, it
can be any incoming ICMPv4 packets if ICMPv4
processing is disabled or incoming ICMPv4
packets that exceed the ICMPv4 rate-limit
threshold.
Discontinuities in the value of this counter can
occur at re-initialization of the management
system, and at other times as indicated by
the value of 'discontinuity-time'.";
}
leaf hairpin-ipv4-packets {
type yang:zero-based-counter64;
description
"IPv4 packets locally routed between two CEs
(hairpinned).
Discontinuities in the value of this counter can
occur at re-initialization of the management
system, and at other times as indicated by
the value of 'discontinuity-time'.";
}
leaf hairpin-ipv4-bytes {
type yang:zero-based-counter64;
description
"IPv4 bytes locally routed between two CEs
(hairpinned).
Discontinuities in the value of this counter can
occur at re-initialization of the management
system, and at other times as indicated by
the value of 'discontinuity-time'.";
}
leaf active-softwire-num {
type uint32;
config false;
description
"The number of currently active softwires on the
binding instance.
Discontinuities in the value of this counter can
occur at re-initialization of the management
system, and at other times as indicated by
the value of 'discontinuity-time'.";
}
}
}
}
}
case algo {
if-feature "map-e or map-t";
container algorithm {
description
" A set of parameters used for MAP-E/MAP-T.";
list algo-instance {
key "name";
description
"Instances of algorithm";
leaf name {
type string;
mandatory true;
description
"The name is used to uniquely identify an algorithm
instance.
This name can be automatically assigned
or explicitly configured.";
}
uses softwire-common:algorithm-instance;
container port-set {
description
"Indicates a set of ports.";
uses port-set;
}
container traffic-stat {
config false;
description
"Traffic statistics information for the BR.";
leaf discontinuity-time {
type yang:date-and-time;
mandatory true;
description
"The time of the most recent occasion on which the BR
instance suffered a discontinuity. This must be
reset to the current date-and-time when the BR
instance is configured or rebooted.";
}
uses softwire-common:traffic-stat;
}
}
}
}
}
}
/*
* Notifications
*/
notification softwire-binding-instance-event {
if-feature "binding-mode";
description
"Notifications for binding instance when an entry is
added, modified, or is not valid anymore.";
leaf bind-name {
type leafref {
path "/br-instances/binding/bind-instance/name";
}
description
"The ID of the binding-instance that
generated the notification.";
}
leaf-list invalid-entry {
type leafref {
path
"/br-instances/binding/"
+ "bind-instance[name=current()/../bind-name]/"
+ "binding-table/binding-entry/binding-ipv6info";
}
description
"Notify the client that a specific binding entry has
expired or is 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
gets other information from the binding BR about the entry
indexed by that ipv6 address.";
}
leaf-list modified-entry {
type leafref {
path
"/br-instances/binding/"
+ "bind-instance[name=current()/../bind-name]/"
+ "binding-table/binding-entry/binding-ipv6info";
}
description
"The ID of the the binding-table entry that
has been modified.";
}
}
notification softwire-algorithm-instance-event {
if-feature "map-e or map-t";
description
"Notifications for algorithm instance when an entry is
added, modified, or is not valid anymore.";
leaf algo-name {
type leafref {
path "/br-instances/algorithm/algo-instance/name";
}
mandatory true;
description
"algorithmic instance event.";
}
leaf-list invalid-entry {
type leafref {
path "/br-instances/algorithm/algo-instance/name";
}
description
"Invalid entry event.";
}
leaf-list added-entry {
type leafref {
path "/br-instances/algorithm/algo-instance/name";
}
description
"Added entry.";
}
leaf-list modified-entry {
type leafref {
path "/br-instances/algorithm/algo-instance/name";
}
description
"Modified entry.";
}
}
}
]]>This module imports typedefs from .The following YANG module contains definitions that are used by both
the softwire CE and softwire BR YANG modules.file "ietf-softwire-common@2018-10-23.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;
reference "Section 4 of RFC 6991";
}
import ietf-yang-types {
prefix yang;
reference "Section 3 of RFC 6991";
}
organization
"IETF Softwire Working Group";
contact
"WG Web:
WG List:
Author: Qi Sun
Author: Linhui Sun
Author: Yong Cui
Author: Ian Farrer
Author: Sladjana Zoric
Author: Mohamed Boucadair
Author: Rajiv Asati
";
description
"This document defines a YANG module defining types
common to all A+P modules.
Copyright (c) 2018 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD License
set forth in Section 4.c of the IETF Trust's Legal Provisions
Relating to IETF Documents
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see
the RFC itself for full legal notices.";
revision 2018-10-23 {
description
"Initial revision.";
reference
"RFC XXXX: YANG Modules for IPv4-in-IPv6 Address plus Port
Softwires";
}
feature map-e {
description
"MAP-E is an IPv6 transition mechanism for transporting IPv4
packets across an IPv6 network using IP encapsulation. MAP-E
allows for a reduction of the amount of centralized state using
rules to express IPv4/IPv6 address mappings. This introduces an
algorithmic relationship between the IPv6 subnet and IPv4
address.
This feature indicates that the network element can function as
one or more MAP-E softwire instances.";
reference
"RFC7597: Mapping of Address and Port with Encapsulation (MAP-E)";
}
feature map-t {
description
"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 that the network element can function as
one or more MAP-T softwire instances.";
reference
"RFC7599: Mapping of Address and Port using Translation (MAP-T)";
}
/*
* Groupings
*/
grouping algorithm-instance {
description
"A collection of parameters that is used fro MAP-E/MAP-T.";
leaf id {
type uint32;
description
"An identifier used to uniquely identify an algorithm
instance.";
}
leaf enable {
type boolean;
description
"Enable/disable an individual MAP-E or MAP-T rule.";
}
container algo-versioning {
description
"Version number for this algorithm instance";
leaf version {
type uint64;
description
"A version number for the mapping algorithm
rules provided to the algorithm instance";
}
leaf date {
type yang:date-and-time;
description
"Timestamp when the algorithm instance was activated.
An algorithm instance may be provided with mapping
rules that may change in time (for example, increase
the size of the port set). When an abuse party
presents an external IP address/port, the version
of the algorithm is important because depending on
the version, a distinct customer may be identified.
The timestamp is used as a key to find the appropriate
algorithm that was put into effect when an abuse
occurred. ";
reference
"RFC7422: Deterministic Address Mapping to Reduce
Logging in Carrier-Grade NAT Deployments";
}
}
choice data-plane {
description
"Selects MAP-E (encapsulation) or MAP-T
(translation)";
case encapsulation {
if-feature "map-e";
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 {
if-feature "map-t";
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 identifying 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 Basic Mapping Rule (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 and forwarded IPv4 packets.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf sent-ipv4-bytes {
type yang:zero-based-counter64;
description
"Decapsulated/translated IPv4 traffic sent, in bytes
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf sent-ipv6-packets {
type yang:zero-based-counter64;
description
"Number of encapsulated IPv6 packets sent.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf sent-ipv6-bytes {
type yang:zero-based-counter64;
description
"Encapsulated IPv6 traffic sent, in bytes
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf rcvd-ipv4-packets {
type yang:zero-based-counter64;
description
"Number of incoming IPv4 packets at the
Internet-facing interface.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf rcvd-ipv4-bytes {
type yang:zero-based-counter64;
description
"IPv4 traffic received for processing, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf rcvd-ipv6-packets {
type yang:zero-based-counter64;
description
"Number of IPv4-in-IPv6 packets received.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf rcvd-ipv6-bytes {
type yang:zero-based-counter64;
description
"IPv4-in-IPv6 traffic received, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf dropped-ipv4-packets {
type yang:zero-based-counter64;
description
"Number of IPv4 packets dropped at the
Internet-facing interface.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf dropped-ipv4-bytes {
type yang:zero-based-counter64;
description
"IPv4 traffic dropped at the Internet-facing
interface, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf dropped-ipv6-packets {
type yang:zero-based-counter64;
description
"Number of IPv4-in-IPv6 packets dropped.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf dropped-ipv6-bytes {
type yang:zero-based-counter64;
description
"IPv4-in-IPv6 traffic dropped, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf dropped-ipv4-fragments {
type yang:zero-based-counter64;
description
"Number of fragmented IPv4 packets dropped.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf dropped-ipv4-fragment-bytes {
type yang:zero-based-counter64;
description
"Fragmented IPv4 traffic dropped, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf ipv6-fragments-reassembled {
type yang:zero-based-counter64;
description
"Number of IPv6 fragments successfully reassembled.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf ipv6-fragments-bytes-reassembled {
type yang:zero-based-counter64;
description
"IPv6 fragments successfully reassembled, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf out-icmpv4-error-packets {
type yang:zero-based-counter64;
description
"Internally generated ICMPv4 error packets.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf out-icmpv4-error-bytes {
type yang:zero-based-counter64;
description
"Internally generated ICMPv4 error messages, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf out-icmpv6-error-packets {
type yang:zero-based-counter64;
description
"Internally generated ICMPv6 error packets.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
leaf out-icmpv6-error-bytes {
type yang:zero-based-counter64;
description
"Internally generated ICMPv6 error messages, in bytes.
Discontinuities in the value of this counter can occur
at re-initialization of the management system, and at
other times as indicated by the value of
'discontinuity-time'.";
}
}
}
]]>The YANG modules defined in this document is designed to be accessed
via network management protocols such as NETCONF or RESTCONF . The
lowest NETCONF layer is the secure transport layer, and the
mandatory-to-implement secure transport is Secure Shell (SSH) . The lowest RESTCONF layer is HTTPS, and the
mandatory-to-implement secure transport is TLS .The NETCONF access control model
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.This document requests IANA to assign a new tunnel type under
"tunnelType" sub-registry (under "ifType definitions" registry): aplusp: A+P Encapsulation [RFCXXXX].This document requests IANA to register the following URIs in the
"IETF XML Registry" :This document requests that IANA registers the following YANG modules
in the "YANG Module Names" registry :This document defines the initial version of the IANA-maintained
iana-tunnel-type YANG module. IANA is requested to add this note:Tunnel type values must not be directly added to the
iana-tunnel-type YANG module. They must instead be respectively
added to the "tunnelType" sub-registry (under "ifType definitions"
registry).When a tunnel type is added to the "tunnelType" registry, a new
"identity" statement must be added to the iana-tunnel-type YANG module.
The name of the "identity" is the same as the corresponding enumeration
in the IANAifType-MIB. The following substatements to the "identity"
statement should be defined:Contains the value of the tunnel
type in lowercase.Replicate the description
from the registry.Replicate the reference from
the registry and add the title of the document.Unassigned or reserved values are not present in the module.When the iana-tunnel-type YANG module is updated, a new "revision"
statement must be added in front of the existing revision
statements.IANA is requested to add this note to "tunnelType" registry:When this registry is modified, the YANG module iana-tunnel-type
must be updated as defined in [RFCXXXX].The authors would like to thank Lishan Li, Bert Wijnen, Giles Heron,
Ole Troan, Andy Wingo and Leo Tietz for their contributions to this
work.Thanks to Sheng Jiang for the review.Special thanks to Tom Petch for the detailed review and
suggestions.The following individuals contributed to this document:The following sections provide examples of how the softwire YANG
modules can be used for configuring softwire elements.The lwAFTR maintains an address binding table which contains the
following 3-tuples:IPv6 Address for a single lwB4Public IPv4 AddressRestricted port-setThe 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:2001:db8::1192.0.2.10x3482001:db8:1::2mybinding-instance2001:db8::1192.0.2.15282001:db8:1::2102415401500
]]>A MAP-E BR is configured with forward mapping rules for the CEs it
is serving. In this example (taken from , Appendix A, Example 2), the following
parameters are required:Rule IPv6 PrefixRule IPv4 PrefixRule EA-bit bit lengthIPv6 Address of MAP-BRThe 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:encapsulation2001:db8::/40192.0.2.0/24162001:db8:ffff::1 provides the example MAP-E
BR configuration xml.myalgo-instance2001:db8:ffff::116192.0.2.0/242001:db8::/40true68
]]>This 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:2001:db8::1192.0.2.10x3482001:db8:1::2lw4o6-waniana-tunnel-type:aplusp
2001:db8:1::2
2001:db8::1
]]>In the example depicted in , the interface name is defined
for the softwire tunnel. This name is then referenced by the routing
configuration for the IPv4 route. provides an example
configuration for the CE's IPv4 routing, using the YANG module
described in .staticv40.0.0.0/0lw4o6-wan
]]> provides an example
configuration for the CE's NAPT44 function, using the YANG module
described in .111192.0.2.168521801863217161192.0.2.1/32192.168.1.0/2462192.0.2.1/32192.168.1.0/24173192.0.2.1/32192.168.1.0/241
]]>