Network Working Group M. Boucadair
Internet-Draft C. Jacquenet
Intended status: Standards Track Orange
Expires: April 12, 2018 S. Sivakumar
Cisco Systems
October 9, 2017
YANG Data Modules for the DS-Lite
draft-ietf-softwire-dslite-yang-07
Abstract
This document defines YANG modules for the DS-Lite Address Family
Transition Router (AFTR) and Basic Bridging BroadBand (B4) elements .
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 12, 2018.
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4
2. DS-Lite YANG Modules: An Overview . . . . . . . . . . . . . . 4
3. DS-Lite AFTR YANG Module . . . . . . . . . . . . . . . . . . 7
4. DS-Lite B4 YANG Module . . . . . . . . . . . . . . . . . . . 13
5. Security Considerations . . . . . . . . . . . . . . . . . . . 16
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 17
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 17
8.1. Normative references . . . . . . . . . . . . . . . . . . 17
8.2. Informative references . . . . . . . . . . . . . . . . . 18
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 21
1. Introduction
This document defines data models for DS-Lite [RFC6333], using the
YANG data modeling language [RFC7950]. Both the Address Family
Transition Router (AFTR) and Basic Bridging BroadBand (B4) elements
are covered by this specification. As a reminder, Figure 1
illustrates an overview of the DS-Lite architecture that involves
AFTR and B4 elements.
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+-----------+
| Host |
+-----+-----+
|10.0.0.1
|
|
|10.0.0.2
+---------|---------+
| | |
| Home router |
|+--------+--------+|
|| B4 ||
|+--------+--------+|
+--------|||--------+
|||2001:db8:0:1::1
|||
|||<-IPv4-in-IPv6 softwire
|||
-------|||-------
/ ||| \
| ISP core network |
\ ||| /
-------|||-------
|||
|||2001:db8:0:2::1
+--------|||--------+
| AFTR |
|+--------+--------+|
|| Concentrator ||
|+--------+--------+|
| |NAT| |
| +-+-+ |
+---------|---------+
|192.0.2.1
|
--------|--------
/ | \
| Internet |
\ | /
--------|--------
|
|198.51.100.1
+-----+-----+
| IPv4 Host |
+-----------+
Figure 1: DS-Lite Base Architecture
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DS-Lite deployment considerations are discussed in [RFC6908].
This document follows the guidelines of [RFC6087], uses the common
YANG types defined in [RFC6991], and adopts Network Management
Datastore Architecture (NMDA).
1.1. Terminology
This document makes use of the terms defined in Section 3 of
[RFC6333].
The terminology for describing YANG data modules is defined in
[RFC7950].
The meaning of the symbols in tree diagrams is defined in
[I-D.ietf-netmod-yang-tree-diagrams].
2. DS-Lite YANG Modules: An Overview
As shown in Figure 1:
o The AFTR element is a combination of an IPv4-in-IPv6
encapsualtion/decapsulation function and a NAT function.
o The B4 element is an IPv4-in-IPv6 encapsulation function.
Therefore, the AFTR YANG module is designed to augment both the
Interfaces YANG module [RFC7223] and the NAT YANG module
[I-D.ietf-opsawg-nat-yang] with DS-Lite specific features. The B4
YANG module augments the interfaces YANG module.
Concretely, the AFTR YANG module (Figure 2) augments the Interfaces
YANG module with the following:
o An IPv6 address used by the AFTR for sending and receiving IPv4-
in-IPv6 packets (aftr-ipv6-address).
o An IPv4 address that is used by the AFTR for troubleshooting
purposes (aftr-ipv4-address): According to [RFC6333], that address
can be used to report ICMP problems and will appear in traceroute
outputs.
o The tunnel MTU to avoid fragmentation (tunnel-mtu): Since using an
IPv4-in-IPv6 encapsulation to carry IPv4 traffic over IPv6 reduces
the effective MTU of the datagram, operators should be able to
increase the MTU size by at least 40 bytes to accommodate both the
IPv6 encapsulation header and the IPv4 datagram without
fragmenting the IPv6 packet (Section 2.2 of [RFC6908]).
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o A policy to limit the number of DS-Lite softwires per subscriber
(max-softwire-per-subscriber): This policy aims to prevent a
misbehaving subscriber from mounting several DS-Lite softwires
that would consume additional AFTR resources (e.g., get more
external ports if the quota were enforced on a per-softwire basis,
consume extra processing due to a large number of active
softwires) [RFC7785].
o A DSCP marking policy to be followed when encapsulating/
decapsulating packets (v6-v4-dscp-preservation): Section 2.10 of
[RFC6908] discusses the uniform model which assumes that
implementations of this model copy the DSCP value to the outer IP
header at encapsulation and copy the outer header's DSCP value to
the inner IP header at decapsulation. Operators should configure
the AFTR so that it copies the DSCP value in the IPv4 header to
the Traffic Class field in the IPv6 header, and vice versa.
In addition, the AFTR YANG module augments the NAT YANG module (nat-
policy, in particular) with the following:
o A policy to instruct the AFTR whether a state can be automatically
migrated (state-migrate): This policy avoids stale mappings at the
AFTR and minimizes the risk of service disruption for subscribers.
According to [RFC7785], the AFTR should migrate existing state to
be bound to the new IPv6 address in the event a new IPv6 address
is assigned to the B4 element. This operation ensures that
traffic destined to the previous B4's IPv6 address will be
redirected to the newer B4's IPv6 address.
o An instruction to rewrite the TCP Maximum Segment Size (MSS)
option (mss-clamping) to avoid TCP fragmentation.
Given that the NAT44 table of the AFTR element is extended to include
the source IPv6 address of incoming packets, the AFTR YANG module
augments the NAT mapping-entry with the following:
o b4-ipv6-address which is used to record the source IPv6 address of
a packet received from a B4 element. This IPv6 address is
required to disambiguate between the overlapping IPv4 address
space of customers.
o The value of the Traffic Class field in the IPv6 header as
received from a B4 element (v6-dscp): This information is used to
preserve DSCP marking when encapsulating/decapsulationg at the
AFTR.
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o The IPv4 DSCP marking of the IPv4 packet received from a B4
element (internal-v4-dscp): This information can be used by the
AFTR fro enforcing the poi
o The IPv4 DSCP marking as set by the AFTR in its external interface
(external-v4-dscp): An AFTR can be instructed to preserve the same
marking or to set it to another value when forwarding an IPv4
packet upstream.
module: ietf-dslite-aftr
augment /if:interfaces/if:interface:
+--rw aftr-ipv6-address? inet:ipv6-address
+--rw aftr-ipv4-address? inet:ipv4-address
+--rw tunnel-mtu? uint16
+--rw max-softwire-per-subscriber? uint8
+--rw v6-v4-dscp-preservation? boolean
augment /nat:nat-module/nat:nat-instances/nat:nat-instance/nat:nat-policy:
+--rw state-migrate? boolean
+--rw mss-clamping
+--rw mss-clamping-enable? boolean
+--rw mss-value? uint16
augment /nat:nat-module/nat:nat-instances/nat:nat-instance/nat:mapping-table/nat:mapping-entry:
+--rw b4-ipv6-address? inet:ipv6-address
+--rw v6-dscp? uint8
+--rw internal-v4-dscp? uint8
+--rw external-v4-dscp? uint8
Figure 2: YANG Module for DS-Lite AFTR
Examples to illustrate the use of this module are provided in
Appendix A.
The B4 YANG module (Figure 3) augments the Interfaces YANG module
with the following:
o An IPv6 address used by a B4 element for sending and receiving
IPv4-in-IPv6 packets (b4-ipv6-address).
o The IPv6 address of the AFTR to use by a B4 element (aftr-
ipv6-addr).
o An IPv4 address that is used by a B4 element for troubleshooting
purposes (b4-ipv4-address).
o The tunnel MTU at the B4 side to avoid fragmentation (tunnel-mtu).
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o An instruction whether DSCP marking is to preserved when
encapsulating an IPv4 packet in an IPv6 packet (v6-v4-dscp-
preservation).
module: ietf-dslite-b4
augment /if:interfaces/if:interface:
+--rw b4-ipv6-address? inet:ipv6-address
+--rw aftr-ipv6-addr? inet:ipv6-address
+--rw b4-ipv4-address? inet:ipv4-address
+--rw tunnel-mtu? uint16
+--rw v6-v4-dscp-preservation? boolean
Figure 3: YANG Module for DS-Lite B4
PCP-related considerations are out of scope of the document. A YANG
module for PCP is documented in [I-D.boucadair-pcp-yang].
3. DS-Lite AFTR YANG Module
<CODE BEGINS> file "ietf-dslite-aftr@2017-10-09.yang"
module ietf-dslite-aftr {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-dslite-aftr";
prefix dslite-aftr;
import ietf-inet-types { prefix inet; }
import ietf-interfaces { prefix if; }
import iana-if-type { prefix ianaift; }
import ietf-nat {prefix nat;}
organization "Softwire Working Group";
contact
"Mohamed Boucadair <mohamed.boucadair@orange.com>
Christian Jacquenet <christian.jacquenet@orange.com>
Senthil Sivakumar <ssenthil@cisco.com>";
description
"This module is a YANG module for DS-Lite AFTR
implementations.
Copyright (c) 2017 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
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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 2017-10-09 {
description "Early yangdoctors review.";
reference "-ietf-07";
}
revision 2017-08-10 {
description "The module augments also the Interface module.";
reference "-ietf-04";
}
revision 2017-07-27 {
description "Redesign the module as an augment of the NAT YANG module.";
reference "-ietf-04";
}
revision 2017-07-03 {
description "Fix some minor points.";
reference "-ietf-03";
}
revision 2017-01-03 {
description "Fixed a compilation error:
https://github.com/mbj4668/pyang/issues/296.";
reference "-ietf-02";
}
revision 2016-11-14 {
description "Integrates the comments from Ian:
add B4 module, add an MSS leaf, add more details about
logging protocols, and other edits.";
reference "-ietf-01";
}
revision 2016-07-27 {
description "-00 IETF version.";
reference "-ietf-00";
}
revision 2016-06-13 {
description "Update the module.";
reference "-04";
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}
revision 2015-12-16 {
description "Fix an error.";
reference "-03";
}
revision 2015-09-01 {
description "Add port threshold notifications.";
reference "-02";
}
revision 2015-08-31 {
description "Fix a timeout issue.";
reference "-01";
}
revision 2015-08-17 {
description "First spec.";
reference "-00";
}
// Augment Interface module with DS-Lite Softwire
augment "/if:interfaces/if:interface" {
when "if:type = 'ianaift:tunnel'";
description
"Augments Interface module with AFTR parameters.
IANA interface types are maintained at this registery:
https://www.iana.org/assignments/ianaiftype-mib/ianaiftype-mib.
tunnel (131), -- Encapsulation interface";
leaf aftr-ipv6-address {
type inet:ipv6-address;
description
"IPv6 address of the DS-Lite AFTR.";
reference
"RFC 6333.";
}
leaf aftr-ipv4-address {
type inet:ipv4-address;
default "192.0.0.1";
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description
"IPv4 address of the DS-Lite AFTR.
192.0.0.1 is reserved for the AFTR element.
This address can be used to report ICMP
problems and will appear in traceroute
outputs.";
reference
"RFC 6333.";
}
leaf tunnel-mtu {
type uint16;
description
"Configures a tunnel MTU.
[RFC6908] specifies that since
fragmentation and reassembly is not
optimal, the operator should do
everything possible to eliminate
the need for it. If the operator uses
simple IPv4-in-IPv6 softwire, it is
recommended that the MTU size of the IPv6
network between the B4 and the AFTR
accounts for the additional overhead
(40 bytes).";
reference
"RFC 6908.";
}
leaf max-softwire-per-subscriber {
type uint8;
default 1;
description
"Configures the maximum softwires per subscriber
feature.
A subscriber is uniquely identified by means
of subscriber-mask.
This policy aims to prevent a misbehaving
subscriber from mounting several DS-Lite
softwires that would consume additional AFTR
resources (e.g., get more external ports if
the quota were enforced on a per-softwire basis,
consume extra processing due to a large number
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of active softwires).";
reference
"Section 4 of RFC 7785.";
}
leaf v6-v4-dscp-preservation {
type boolean;
description
"Copies the DSCP value from the IPv6 header
and vice versa.
According to Section 2.10 of [RFC6908],
operators should use this model
by provisioning the network such that
the AFTR copies the DSCP value in the IPv4
header to the Traffic Class field in
the IPv6 header, after the encapsulation
for the downstream traffic.";
reference
"Section 2.10 of RFC 6908.";
}
}
// Augment NAT module with AFTR parameters
augment "/nat:nat-module/nat:nat-instances/"+
"nat:nat-instance/nat:nat-policy" {
when "../nat:nat-capabilities/nat:nat-flavor = 'nat:nat44'";
description
"Augments the NAT44 module with AFTR parameters.";
leaf state-migrate {
type boolean;
default true;
description
"State migration is enabled by default.
In the event a new IPv6 address is assigned to the B4 element,
the AFTR should migrate existing state to be bound to the new
IPv6 address. This operation ensures that traffic destined to
the previous B4's IPv6 address will be redirected to the newer
B4's IPv6 address. The destination IPv6 address for tunneling
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return traffic from the AFTR should be the last seen as the B4's
IPv6 source address from the CPE.
The AFTR uses the subscriber-mask to determine whether two
IPv6 addresses belong to the same CPE (e.g., if the
subscriber-mask is set to 56, the AFTR concludes that
2001:db8:100:100::1 and 2001:db8:100:100::2 belong to the same
CPE assigned with 2001:db8:100:100::/56).";
reference
"RFC 7785.";
}
container mss-clamping {
description
"MSS rewriting configuration to avoid IPv6
fragmentation.";
leaf mss-clamping-enable {
type boolean;
description
"Enable/disable MSS rewriting feature.";
}
leaf mss-value {
type uint16;
units "octets";
description
"Sets the MSS value to be used for
MSS rewriting.";
}
}
}
// Augment NAT mapping entry: Extended NAT44 mapping Entry
augment "/nat:nat-module/nat:nat-instances/nat:nat-instance/"+
"nat:mapping-table/nat:mapping-entry"{
when "../../nat:nat-capabilities/nat:nat-flavor = 'nat:nat44'";
description
"Augments the NAT44 mapping table with DS-Lite specifics.";
leaf b4-ipv6-address {
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type inet:ipv6-address;
description
"Corresponds to the IPv6 address
used by the B4 element.";
reference
"RFC 6333.";
}
leaf v6-dscp {
type uint8;
description
"DSCP value used at the softwire level
(i.e., IPv6 header).";
}
leaf internal-v4-dscp {
type uint8;
description
"DSCP value of the encapsulated IPv4 packet.";
}
leaf external-v4-dscp {
type uint8;
description
"DSCP value of the translated IPv4 packet
as marked by the AFTR.";
}
}
}
<CODE ENDS>
4. DS-Lite B4 YANG Module
<CODE BEGINS> file "ietf-dslite-b4@2017-10-09.yang"
module ietf-dslite-b4 {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-dslite-b4";
prefix dslite-b4;
import ietf-inet-types { prefix inet; }
import ietf-interfaces { prefix if; }
import iana-if-type { prefix ianaift; }
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organization "Softwire Working Group";
contact
"Mohamed Boucadair <mohamed.boucadair@orange.com>
Christian Jacquenet <christian.jacquenet@orange.com>
Senthil Sivakumar <ssenthil@cisco.com>";
description
"This module is a YANG module for DS-Lite B4 implementations.
Copyright (c) 2017 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 2017-10-09 {
description "Early yangdoctors review.";
reference "-ietf-07";
}
revision 2017-08-10 {
description "Augment the interfaces YANG module.";
reference "-ietf-05";
}
revision 2017-07-27 {
description "Separate B4 from AFTR.";
reference "-ietf-04";
}
// Augment Interface module with DS-Lite Softwire
augment "/if:interfaces/if:interface" {
when "if:type = 'ianaift:tunnel'";
description
"Augments Interface module with B4 parameters.
IANA interface types are maintained at this registry:
https://www.iana.org/assignments/ianaiftype-mib/ianaiftype-mib.
tunnel (131), -- Encapsulation interface";
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leaf b4-ipv6-address {
type inet:ipv6-address;
description
"The IPv6 address used by the B4 element.";
reference
"RFC 6333.";
}
leaf aftr-ipv6-addr {
type inet:ipv6-address;
description
"The AFTR's IPv6 address.";
reference
"RFC 6333.";
}
leaf b4-ipv4-address {
type inet:ipv4-address;
default "192.0.0.2";
description
"IPv4 address of the DS-Lite B4.
192.0.0.0/29 is reserved for the B4 element.
This address can be used to report ICMP
problems and will appear in traceroute
outputs.";
reference
"RFC 6333.";
}
leaf tunnel-mtu {
type uint16;
description
"Configures a tunnel MTU.
[RFC6908] specifies that since
fragmentation and reassembly is not
optimal, the operator should do
everything possible to eliminate
the need for it. If the operator uses
simple IPv4-in-IPv6 softwire, it is
recommended that the MTU size of the IPv6
network between the B4 and the AFTR
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accounts for the additional overhead
(40 bytes).";
reference
"RFC 6908.";
}
leaf v6-v4-dscp-preservation {
type boolean;
description
"Copies the DSCP value from the IPv6 header
and vice versa.
Operators should use this model
by provisioning the network such that
the AFTR copies the DSCP value in the IPv4
header to the Traffic Class field in
the IPv6 header, after the encapsulation
for the downstream traffic.";
reference
"Section 2.10 of RFC 6908.";
}
}
}
<CODE ENDS>
5. 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 support of SSH is mandatory to
implement secure transport [RFC6242]. The NETCONF access control
model [RFC6536] provides means to restrict access for particular
NETCONF users to a pre-configured subset of all available NETCONF
protocol operations and contents.
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.
6. IANA Considerations
This document requests IANA to register the following URIs in the
"IETF XML Registry" [RFC3688]:
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URI: urn:ietf:params:xml:ns:yang:ietf-dslite-aftr
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.
URI: urn:ietf:params:xml:ns:yang:ietf-dslite-b4
Registrant Contact: The IESG.
XML: N/A; the requested URI is an XML namespace.
This document requests IANA to register the following YANG modules in
the "YANG Module Names" registry [RFC7950].
name: ietf-dslite-aftr
namespace: urn:ietf:params:xml:ns:yang:ietf-dslite-aftr
prefix: dslite-aftr
reference: RFC XXXX
name: ietf-dslite-b4
namespace: urn:ietf:params:xml:ns:yang:ietf-dslite-b4
prefix: dslite-b4
reference: RFC XXXX
7. Acknowledgements
Thanks to Q. Wu for identifying a compiling error. Mahesh
Jethanandani provided an eraly ynagdoctors review; many thanks to
him.
Many thanks to Ian Farrer for the review and comments
8. References
8.1. Normative references
[I-D.ietf-opsawg-nat-yang]
Boucadair, M., Sivakumar, S., Jacquenet, C., Vinapamula,
S., and Q. Wu, "A YANG Data Model for Network Address
Translation (NAT) and Network Prefix Translation (NPT)",
draft-ietf-opsawg-nat-yang-05 (work in progress), October
2017.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<https://www.rfc-editor.org/info/rfc3688>.
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[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,
<https://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,
<https://www.rfc-editor.org/info/rfc6242>.
[RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual-
Stack Lite Broadband Deployments Following IPv4
Exhaustion", RFC 6333, DOI 10.17487/RFC6333, August 2011,
<https://www.rfc-editor.org/info/rfc6333>.
[RFC6536] Bierman, A. and M. Bjorklund, "Network Configuration
Protocol (NETCONF) Access Control Model", RFC 6536,
DOI 10.17487/RFC6536, March 2012,
<https://www.rfc-editor.org/info/rfc6536>.
[RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types",
RFC 6991, DOI 10.17487/RFC6991, July 2013,
<https://www.rfc-editor.org/info/rfc6991>.
[RFC7223] Bjorklund, M., "A YANG Data Model for Interface
Management", RFC 7223, DOI 10.17487/RFC7223, May 2014,
<https://www.rfc-editor.org/info/rfc7223>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>.
8.2. Informative references
[I-D.boucadair-pcp-yang]
Boucadair, M., Jacquenet, C., Sivakumar, S., and S.
Vinapamula, "YANG Data Models for the Port Control
Protocol (PCP)", draft-boucadair-pcp-yang-04 (work in
progress), May 2017.
[I-D.ietf-netmod-yang-tree-diagrams]
Bjorklund, M. and L. Berger, "YANG Tree Diagrams", draft-
ietf-netmod-yang-tree-diagrams-01 (work in progress), June
2017.
[RFC6087] Bierman, A., "Guidelines for Authors and Reviewers of YANG
Data Model Documents", RFC 6087, DOI 10.17487/RFC6087,
January 2011, <https://www.rfc-editor.org/info/rfc6087>.
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Internet-Draft DS-Lite YANG October 2017
[RFC6908] Lee, Y., Maglione, R., Williams, C., Jacquenet, C., and M.
Boucadair, "Deployment Considerations for Dual-Stack
Lite", RFC 6908, DOI 10.17487/RFC6908, March 2013,
<https://www.rfc-editor.org/info/rfc6908>.
[RFC7785] Vinapamula, S. and M. Boucadair, "Recommendations for
Prefix Binding in the Context of Softwire Dual-Stack
Lite", RFC 7785, DOI 10.17487/RFC7785, February 2016,
<https://www.rfc-editor.org/info/rfc7785>.
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Appendix A. Examples
The following example shows an AFTR that is reachable at 2001:db8::2.
Also, this XML snippet indicates that the AFTR is provided with an
IPv4 address (192.0.0.1) to be used for troubleshooting purposes such
as reporting problems to B4s. Moreover, the AFTR is instructed to
limit the number of softwires per subscriber to '1'.
<interface>
<name>myAFTR</name>
<type>ianaift:tunnel</type>
<enabled>true</enabled>
<aftr-ipv6-address>2001:db8::2</aftr-ipv6-address>
<aftr-ipv4-address>192.0.0.1</aftr-ipv4-address>
<max-softwire-per-subscriber>1</max-softwire-per-subscriber>
</interface>
The following shows an XML excerpt depicting a dynamic UDP mapping
entry maintained by a DS-Lite AFTR. In reference to this example,
the UDP packet received with a source IPv6 address (2001:db8::1), a
source IPv4 address (192.0.2.1) and source port number (1568) is
translated into a UDP packet having a source IPv4 address
(198.51.100.1) and source port (15000). The lifetime of this mapping
is 300 seconds.
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<mapping-entry>
<index>15</index>
<type>
dynamic-explicit
</type>
<transport-protocol>
17
</transport-protocol>
<b4-ipv6-address>
2001:db8::1
</b4-ipv6-address>
<internal-src-address>
192.0.2.1
</internal-dst-address>
<internal-src-port>
<single-port-number>
1568
</single-port-number>
</internal-dst-port>
<external-dst-address>
198.51.100.1
</external-dst-address>
<external-dst-port>
<single-port-number>
15000
</single-port-number>
</external-dst-port>
<lifetime>
300
</lifetime>
</mapping-entry>
Authors' Addresses
Mohamed Boucadair
Orange
Rennes 35000
France
EMail: mohamed.boucadair@orange.com
Christian Jacquenet
Orange
Rennes 35000
France
EMail: christian.jacquenet@orange.com
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Senthil Sivakumar
Cisco Systems
7100-8 Kit Creek Road
Research Triangle Park, North Carolina 27709
USA
Phone: +1 919 392 5158
EMail: ssenthil@cisco.com
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