Internet DRAFT - draft-ietf-softwire-dslite-deployment
draft-ietf-softwire-dslite-deployment
Softwire Y. Lee
Internet-Draft Comcast
Intended status: Informational R. Maglione
Expires: July 21, 2013 Telecom Italia
C. Williams
MCSR Labs
C. Jacquenet
M. Boucadair
France Telecom
January 17, 2013
Deployment Considerations for Dual-Stack Lite
draft-ietf-softwire-dslite-deployment-08
Abstract
This document discusses the deployment issues and describes
requirements for the deployment and operation of Dual-Stack Lite.
This document describes the various deployment considerations and
applicability of the Dual-Stack Lite architecture.
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 July 21, 2013.
Copyright Notice
Copyright (c) 2013 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
Lee, et al. Expires July 21, 2013 [Page 1]
Internet-Draft Deployment Considerations for DS-Lite January 2013
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. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. AFTR Deployment Considerations . . . . . . . . . . . . . . . . 3
2.1. Interface Consideration . . . . . . . . . . . . . . . . . 3
2.2. MTU and Fragmentation Considerations . . . . . . . . . . . 4
2.3. Logging at the AFTR . . . . . . . . . . . . . . . . . . . 4
2.4. Blacklisting a Shared IPv4 Address . . . . . . . . . . . . 5
2.5. AFTR's Policies . . . . . . . . . . . . . . . . . . . . . 5
2.5.1. Outgoing Policy . . . . . . . . . . . . . . . . . . . 5
2.5.2. Incoming Policy . . . . . . . . . . . . . . . . . . . 6
2.6. AFTR Impacts on Accounting Process . . . . . . . . . . . . 6
2.7. Reliability Considerations of AFTR . . . . . . . . . . . . 7
2.8. Strategic Placement of AFTR . . . . . . . . . . . . . . . 8
2.9. AFTR Considerations for Geographically Aware Services . . 8
2.10. Impacts on QoS Policy . . . . . . . . . . . . . . . . . . 9
2.11. Port Forwarding Considerations . . . . . . . . . . . . . . 9
2.12. DS-Lite Tunnel Security . . . . . . . . . . . . . . . . . 10
2.13. IPv6-only Network Considerations . . . . . . . . . . . . . 10
3. B4 Deployment Considerations . . . . . . . . . . . . . . . . . 11
3.1. DNS Deployment Considerations . . . . . . . . . . . . . . 11
3.2. IPv4 Service Monitoring . . . . . . . . . . . . . . . . . 11
3.2.1. B4 Remote Management . . . . . . . . . . . . . . . . . 11
3.2.2. IPv4 Connectivity Check . . . . . . . . . . . . . . . 12
4. Security Considerations . . . . . . . . . . . . . . . . . . . 12
5. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 12
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7.1. Normative References . . . . . . . . . . . . . . . . . . . 12
7.2. Informative References . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14
Lee, et al. Expires July 21, 2013 [Page 2]
Internet-Draft Deployment Considerations for DS-Lite January 2013
1. Overview
Dual-stack Lite (DS-Lite) [RFC6333] is a transition technique that
enable operators to multiplex public IPv4 addresses while
provisioning only IPv6 to users. DS-Lite is designed to continue
offering IPv4 services while operators upgrading their network
incrementally to IPv6. DS-Lite combines IPv4-in-IPv6 softwire
[RFC2473] and NAT44 [RFC3022] to enable more than one user to share a
public IPv4 address.
While Appendix A of [RFC6333] explains how to deploy DS-Lite within
specific scenarios, the purpose of this document is to describe
problems that arise when deploying DS-Lite and what guidance should
be taken to mitigate those issues. The information is based on real
deployment experience and compiled in one comprehensive document so
that operators aren't required to search through various RFCs
deciding which sections are applicable and impact their DS-Lite
deployment.
2. AFTR Deployment Considerations
2.1. Interface Consideration
Address Family Transition Router (AFTR) is a network element that
deployed inside the operator's network. AFTR can be a standalone
device or embedded into a router. AFTR is the IPv4-in-IPv6 tunnel
termination point and the NAT44 device. It is deployed at the IPv4-
IPv6 network border where the tunnel interface is IPv6 and the
external NAT44 interface is IPv4. The B4 element [RFC6333] is a
function implemented on a dual-stack capable node, either a host
device or a home gateway that creates a tunnel to an AFTR. Although
an operator can configure both softwire tunnel termination and
interface for NAT44 functions on a single physical interface (yet
logically separated), there are scenarios we recommend to configure
two individual interfaces (i.e. one dedicated for IPv4 and one
dedicated for IPv6) to segregate the functions.
o The access network between the B4 and AFTR is an IPv6-only network
and the network between AFTR and IPv4 network is either IPv4-only
network. In this deployment scenario, the AFTR interface to the
IPv6-only network and the interface to the IPv4 network should use
two physical interfaces on AFTR.
o Operators may use Operations Support System (OSS) tools (e.g.,
Multi Router Traffic Grapher) to collect interface data packet
count information. If an operator wants to separate the softwire
function and NAT44 function on different physical interfaces for
Lee, et al. Expires July 21, 2013 [Page 3]
Internet-Draft Deployment Considerations for DS-Lite January 2013
collecting data packet count and the AFTR does not support packet
count for logical interfaces, they should use two physical
interfaces on AFTR.
2.2. MTU and Fragmentation Considerations
DS-Lite is part tunneling protocol. Tunneling introduces overhead to
the packet and decreases the effective MTU size after encapsulation.
The DS-lite users may experience problems with applications such as
not being able to download Internet pages or transfer large files.
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 [RFC2473], it is
recommended that the MTU size of the IPv6 network between the B4 and
the AFTR account for the additional overhead (40 bytes). If the
access network MTU size is fixed and cannot be changed, the operator
should be aware that the B4 element and the AFTR must support
fragmentation as defined in [RFC6333]. The operator should also be
aware that reassembly at Tunnel Exit-Point is resource intensive as a
large number of B4 may terminate on the same AFTR. Scalability of
the AFTR is advised in this scenario.
2.3. Logging at the AFTR
Source-Specific Log is essential for back tracking specific users
when a problem is identified with one of the AFTR's NAT-ed addresses.
Source-specific log contains the B4 IPv6 source address, transport
protocol, source port, and source IPv4 address after NAT-ed. Using
the Source-specific log, operators can uniquely identify a specific
user when a DS-Lite user experiences problem to access IPv4 network.
To maximize IPv4 shared radio, an operator may configure a short
timeout value for NAT44 entries. This will result a large numbers of
log created by the AFTR. For operators who desire to aggregate the
logs, they can configure AFTR to pre-allocate a range of ports to
each user. This range of ports will be used in the NAT44 function
and the AFTR will create one log entry for the whole port-range.
This aggregation can significantly reduce the log size for Source-
specific logging.
Some operators may require to log both source and destination
information for user's connections. This is called Destination-
Specific Log. Destination-specific log contains the B4's IPv6
address, transport protocol, source port, source IPv4 address after
NAT-ed, destination port and destination IPv4 address. Destination-
specific log is session-based, the operators should be aware that
they will not be able to aggregate log entries. When using
destination-specific log, the operator must be careful of the large
Lee, et al. Expires July 21, 2013 [Page 4]
Internet-Draft Deployment Considerations for DS-Lite January 2013
number of log entries created by the AFTR. Some AFTR implementations
may keep the logs in main memory. This may be CPU and memory
resource intensive. We suggest the operators must configure the AFTR
to periodically send logs to storage facility and then purge them
from AFTR.
2.4. Blacklisting a Shared IPv4 Address
AFTR is a NAT device. It enables multiple users to share a single
public IPv4 address. [RFC6269] discusses some considerations when
sharing an IPv4 address. When a public IPv4 address is blacklisted
by a remote peer, this may affect multiple B4 elements sharing the
same IPv4 address. Operators deploying DS-Lite should be aware that
Internet hosts may rely solely on source IP address to identify an
abusive household and may not be aware that a given single IPv4
address is actually shared by multiple households. A content
provider may block services for a shared IPv4 address and this will
impact all households sharing this particular IPv4 address. The
operator may receive calls of service outage and will need to take
appropriate actions. Such corrective actions include but not limited
to notifying the content provider to combine the IPv4 address with
transport (e.g., TCP) and application protocol (e.g., HTTP) to
identify abusive household. [RFC6302].
[I-D.ietf-intarea-nat-reveal-analysis] analyzes different approaches
to identify a user in a shared address environment.
2.5. AFTR's Policies
There are two types of AFTR policies:
o Outgoing Policies apply to packets originating from B4 to AFTR.
These policies should be provisioned on the AFTR's IPv6 interface
connected to the B4 elements.
o Incoming Policies apply to packets originating from IPv4 network
to B4s. These policies should be provisioned on the IPv4
Interface connected to the IPv4 network.
2.5.1. Outgoing Policy
Outgoing policies may include Access Control List (ACL) and Qualify
of Service (QoS) settings. These policies control the packets from
B4 elements to the AFTR. For example, the operator may configure the
AFTR only to accept B4's connections originated from specific IPv6
prefixes configured in the AFTR. More discussion of this use case
can be found in Section 2.12. An operator may configure the AFTR to
give priority to the packets marked by certain DSCP values [RFC2475].
Furthermore, an AFTR may also apply outgoing policy to limit the rate
Lee, et al. Expires July 21, 2013 [Page 5]
Internet-Draft Deployment Considerations for DS-Lite January 2013
of port allocation for a single B4's IPv6 address.
Some operators offer different service level agreements (SLA) to
users to meet their requirements. Some users may require more ports
and some may require different service priority. In this deployment
scenario, the operator can implement outgoing policies specified to a
user's B4 element or a group of B4 elements sharing the same
policies.
2.5.2. Incoming Policy
Similar to Outgoing Policy, Incoming Policy may also include ACL and
QoS settings. Outgoing Policy controls packets coming from IPv4
network to the B4 elements. Incoming packets are normally treated
equally, so these policies are globally applied. For example, an
operator wants to use a pre-defined DSCP value to signal the IPv6
access network to apply certain traffic policies. In this deployment
scenario, the operator can configure the AFTR to mark the incoming
packets with the pre-defined DSCP value. This policy will apply to
all incoming packets from the IPv4 network.
2.6. AFTR Impacts on Accounting Process
This section discusses IPv4 and IPv6 traffic accounting in DS-Lite
environment. In a typical broadband access scenario (e.g. DSL or
Cable), the B4 element is embedded in the Residential Gateway and the
edge router (e.g., Broadband Network Gateway or Cable Modem
Termination System) is the IPv6 edge router. The edge router is
usually responsible for IPv6 accounting and the user management
functions such as authentication, authorization and accounting (AAA).
However, given the fact that IPv4 traffic is encapsulated in an IPv6
packet at the B4 and only decapsulated at the ATFR, the edge router
will require additional function to associate IPv4 accounting
information to the B4 IPv6 address. If DS-lite is the only
application using IPv4-in-IPv6 protocol in the IPv6 access network,
the operator can configure the edge router to check the IPv6 Next
Header field in the IPv6 header and identify the protocol type (i.e.
0x04) and collect IPv4 accounting information.
Alternatively, AFTR may perform accounting for IPv4 traffic.
However, operators must be aware that this will introduce some
challenges especially in DSL deployment. In DSL deployment, the AAA
transaction normally happens between the edge router (i.e., Broadband
Network Gateway) and AAA server. [RFC6333] does not require the AFTR
to interact with the AAA server or edge router. Thus, AFTR may not
have the AAA parameters (e.g., Account Session ID) associated to
users to generate IPv4 accounting record. The accounting process at
the AFTR is only necessary if the operator requires separating per
Lee, et al. Expires July 21, 2013 [Page 6]
Internet-Draft Deployment Considerations for DS-Lite January 2013
user accounting records for IPv4 and IPv6 traffic. If the per user
IPv6 accounting records, collected by the edge router, are
sufficient, and the additional complexity of enabling IPv4 accounting
at the ATFR is not required. It is important to notice that, since
the IPv4 traffic is encapsulated in IPv6 packets, the data collected
by the edge router for IPv6 traffic already contain the total amount
of traffic (i.e. IPv4 and IPv6).
Even if detailed accounting records collection for IPv4 traffic may
not be required, it would be useful for an operator in some scenarios
to have information the edge router generates that for the IPv6
traffic and can be used to identify the AFTR who is handling the IPv4
traffic for that user. This can be achieved by adding additional
information to the IPv6 accounting records. For example: operators
can use RADIUS attribute information specified in [RFC6519] or a new
attribute to be specified in Internet Protocol Detailed Record
(IPDR).
2.7. Reliability Considerations of AFTR
For robustness, reliability and load distribution purposes, operators
may deploy multiple AFTRs. In such case, the same IPv6 prefixes and
algorithm to build the tunneling mechanisms will be configured on
those AFTRs. In [RFC6333] A.3 mentions High Availability (HA) is the
operator's responsibility. Since DS-lite is a stateful mechanism,
all requirements for load-balancing and failover mechanism apply.
There are many ways to implement HA in stateful mechanism, most
common are Cold Standby mode and Hot Standby mode. More discussion
on deploying of these two modes for NAT can be found in
[I-D.xu-behave-stateful-nat-standby] In Cold Standby mode the AFTR
states are not replicated from the Primary AFTR to the Backup AFTR.
When the Primary AFTR fails, all the existing established sessions
will be flushed out. The internal hosts are required to re-establish
sessions with the external hosts. In Hot Standby mode the user's
states are replicated on-the-fly from the Primary AFTR to the Backup
AFTR. When the Primary AFTR fails, the Backup AFTR will take over
all the existing established sessions. In this mode the internal
hosts are not required to re-establish sessions with the external
hosts.
For operators, the decision to use Cold Standby mode or Hot Standby
mode depends on the trade-off between capital cost and operational
cost. Cold Standby mode does not require a Backup Standby AFTR to
synchronize user states. This simplifies the operational model.
When the Primary AFTR went down, any AFTR with extra capacity could
take over. Hot Standby mode provides a smoother failover experience
to users, the cost for the operators is more careful failover
planning. For most deployment scenarios, we believe that Cold
Lee, et al. Expires July 21, 2013 [Page 7]
Internet-Draft Deployment Considerations for DS-Lite January 2013
Standby mode should be sufficient enough and thus recommended.
2.8. Strategic Placement of AFTR
In DS-Lite environment, AFTR is the logical next-hop router of the B4
elements to access IPv4 network, so the placement of the AFTR will
affect the traffic flows in the access network and overall network
design. In general, there are two placement models to deploy AFTR.
Model One is to deploy the AFTR in the edge of the network to cover a
small region. Model Two is to deploy the AFTR in the core of network
to cover a large region.
When an operator considers where to deploy the AFTR, it must make
trade-offs. AFTR in Model One serves fewer B4 elements, thus, it
requires less powerful AFTR. Moreover, the traffic flows are more
evenly distributed to the AFTRs. However, it requires deploying more
AFTRs to cover the entire network. Often the operation cost
increases proportionally with to the number of network equipment.
AFTR in Model Two covers a larger area, thus, it serves more B4
elements. The operator could deploy only few AFTRs to support the
entire user base. However, this model requires more powerful AFTR to
sustain the load at peak hours. Since AFTR would support B4 elements
from different regions, AFTR would be deployed closer to the core
network.
DS-Lite framework can be incrementally deployed. An operator may
consider to start with Model Two. When the demand increases, the
operator could push the AFTR closer to the edge, which would
effectively become Model One.
2.9. AFTR Considerations for Geographically Aware Services
By centralizing public IPv4 addresses in AFTR, remote services can no
longer rely on an IPv4 address and IPv4 routing information to derive
a user's geographical information. For example, the IPv6 access
network and the AFTR may be in two different cities. If the remote
services rely on the IPv4 address to locate a user, they may have
thought the user was in a different city. [RFC6269] Section 7
describe the problem in more details. Applications could explicitly
ask users to enter location information such as postal code or
telephone number before offering geographical service. In contrast,
applications could use HELD [RFC5985] to get the location information
from the Location Information Server and give this information to the
remote peer. [RFC6280] describes an architecture to enable location-
based services. However to mitigate the impact, we recommend
operators to deploy AFTR as close to users as possible.
Lee, et al. Expires July 21, 2013 [Page 8]
Internet-Draft Deployment Considerations for DS-Lite January 2013
2.10. Impacts on QoS Policy
This section describes the application of [RFC2983] to DS-Lite
deployment model. Operators must ensure that the QoS policy that is
in place operates properly within the DS-Lite deployment. In this
regard, operators commonly use DSCP [RFC2475] to classify and
prioritize different types of traffic in their networks. DS-Lite
tunnel can be seen as a particular case of uniform conceptual tunnel
model described in section 3.1 of [RFC2983]. The uniform model views
an IP tunnel as just a necessary mechanism to forward traffic to its
destination, but the tunnel has no significant impact on traffic
conditioning. In this model, any packet has exactly one DSCP Field
that is used for traffic conditioning at any point and it is the
field in the outermost IP header. In DS-Lite model this is the
Traffic Class field in IPv6 header. According to [RFC2983]
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 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. Similarly the B4 copies the DSCP value in the
IPv4 header to the Traffic Class field to the IPv6 header after the
encapsulation for the upstream traffic. Traffic identification and
classification can be done by examining the outer IPv6 header in the
IPv6 access network.
2.11. Port Forwarding Considerations
Some applications behind the B4 element require the B4 element to
accept incoming requests. If the remote application wants to
communicate to the application behind the B4 element, the remote
application must know both the NAT-ed IPv4 address used by the B4
element and the IPv4 destination port. Some applications use
Universal Plug and Play (UPnP) (e.g., popular gaming consoles) or ICE
[RFC5245] to request incoming ports. Some applications rely on
Application Level Gateway (ALG) or manual port configuration to
reserve a port in the NAT. For the DS-Lite deployment scenario
whereby the B4 does not own a dedicated public IPv4 address or all
the available ports, the operator will manage port-forwarding in the
serving AFTR. Operators may use Port Control Protocol (PCP)
[I-D.ietf-pcp-base] as guidance to provide port-forwarding service.
Operators will deploy PCP client in the B4 elements. PCP permits PCP
server to be deployed in a standalone server. However, we recommend
the operators to consider deploying the PCP server in the AFTR. This
will ease the overhead to design a global configuration for PCP
server for many AFTRs because each PCP server will be dedicated to
Lee, et al. Expires July 21, 2013 [Page 9]
Internet-Draft Deployment Considerations for DS-Lite January 2013
the collocated AFTR.
When sharing an IPv4 address, not all the ports are available to a
user. Some restricted ports (i.e., 0-1023) are well-known such as
TCP port 25 and 80. Many users may want to be provisioned with the
restricted ports. For fairness, we recommend operators to configure
the AFTR not to allocate the restricted ports to regular DS-Lite
users. This operation model ensures that DS-lite users will have
uniform configuration, which can simplify provisioning and operation.
For users who want to use the restricted ports, operators can
consider to provision a full IPv4 address to those users. If an
operator still want to provision restricted ports to specific users,
it may require to implement static user's configuration in the AFTR
to match the B4's IPv6 address to the NAT rules. Alternatively, the
B4 element may dynamically allocate the ports and the AFTR
authenticates the user's request using PCP [I-D.ietf-pcp-base].
2.12. DS-Lite Tunnel Security
[RFC6333] Section 11 describes security issues associated to DS-Lite
mechanism. To restrict the service offered by AFTR only to
registered users, an operator can implement Outgoing Policy on the
AFTR's tunnel interface to accept only the IPv6 prefixes defined in
the policy. For static provisioning, the operator will need to know
in advance the IPv6 prefixes provisioned to the users for the
softwire in order to configure the policy. To simplify operation,
operators should configure the AFTRs in the same region with the same
IPv6 prefixes Outgoing Policy. The AFTRs will accept both regular
connections and failover connections from the B4 elements in the same
service region.
2.13. IPv6-only Network Considerations
In environments where the operator wants to deploy AFTR in the IPv6-
only network, the AFTR nodes may not have direct IPv4 connectivity.
In this scenario the operator extends the IPv6-only boundary to the
border of the network and only the border routers have IPv4
connectivity. For both scalability and performance purposes, AFTR is
located in the IPv6-only network closer to B4 elements. In this
scenario the AFTR has only IPv6 connectivity and must be able to send
and receive IPv4 packets. Enhancements to the DS-Lite AFTR are
required to achieve this. [I-D.boucadair-softwire-dslite-v6only]
describes such issues and enhancements to DS-Lite in IPv6-only
deployments.
Lee, et al. Expires July 21, 2013 [Page 10]
Internet-Draft Deployment Considerations for DS-Lite January 2013
3. B4 Deployment Considerations
In order to configure the IPv4-in-IPv6 tunnel, the B4 element needs
the IPv6 address of the AFTR element. This IPv6 address can be
configured using a variety of methods, ranging from an out-of-band
mechanism, manual configuration, DHCPv6 option to RADIUS. If an
operator uses DHCPv6 to provision the B4, the B4 element must
implement the DHCPv6 option defined in [RFC6334]. If an operator
uses RADIUS to provision the B4, the B4 element must implement
[RFC6519].
3.1. DNS Deployment Considerations
[RFC6333] recommends the B4 element should send DNS queries to an
external recursive resolver over IPv6. The B4 element should
implement proxy resolver that will proxy DNS query from IPv4
transport to the DNS server in the IPv6 network. [RFC6333] does not
describe the DNS proxy behavior. In deployment, the operator must
ensure that the DNS proxy implementation must follow [RFC5625]. This
is important especially for operators who have deployed or consider
to deploy DNSSEC [RFC4035].
Some operators may want to give clients behind the B4's element an
IPv4 address of an external DNS recursive resolver. The B4 element
will treat the DNS packets as normal IP packets and forward over the
softwire. Note that there is no effective way to provision an IPv4
DNS address to the B4 over IPv6, operators who use this DNS
deployment model must be aware that it is undefined how to provision
an IPv4 DNS address over an IPv6 network, so it will introduce
additional complexity in B4 provisioning. Moreover, this will
increase load to AFTR by creating entries in the NAT table for DNS
sessions. Operators may deploy a local DNS caching resolver in AFTR
to reduce the load in the NAT table. Nonetheless, this DNS model is
not covered in [RFC6333] and is not recommended.
3.2. IPv4 Service Monitoring
3.2.1. B4 Remote Management
B4 is connected to IPv6 access network to offer IPv4 services. When
users experience IPv4 connectivity issue, operators must be able to
remotely access (e.g. TR-069) the B4 element to verify its B4's
configuration and status. Operators should access B4 elements using
native IPv6. Operators should not access B4 over the softwire.
Lee, et al. Expires July 21, 2013 [Page 11]
Internet-Draft Deployment Considerations for DS-Lite January 2013
3.2.2. IPv4 Connectivity Check
DS-Lite framework provides IPv4 services over IPv6 access network.
Operators and users must be able to check the IPv4 connectivity from
the B4 element to its AFTR using PING and IPv4 Traceroute. AFTR
should be configured with an IPv4 address to enable PING test and
Traceroute test. Operators should assign the same IPv4 address
(i.e., 192.0.0.2/32) to all AFTRs. IANA allocates 192.0.0.0/29
[RFC6333] Section 5.7 that can be used for this purpose.
4. Security Considerations
This document does not present any new security issues. [RFC6333]
discusses DS-Lite related security issues.
5. Acknowledgement
Thanks to Mr. Nejc Skoberne and Dr. Maoke Chen for their thorough
review and helpful comments. We also want to thank Mr. Hu Jie for
sharing his DS-Lite deployment experience to us. He gave us
recommendations what his company learned while testing DS-Lite in the
production network.
6. IANA Considerations
This memo includes no request to IANA.
7. References
7.1. Normative References
[RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual-
Stack Lite Broadband Deployments Following IPv4
Exhaustion", RFC 6333, August 2011.
[RFC6334] Hankins, D. and T. Mrugalski, "Dynamic Host Configuration
Protocol for IPv6 (DHCPv6) Option for Dual-Stack Lite",
RFC 6334, August 2011.
[RFC6519] Maglione, R. and A. Durand, "RADIUS Extensions for Dual-
Stack Lite", RFC 6519, February 2012.
Lee, et al. Expires July 21, 2013 [Page 12]
Internet-Draft Deployment Considerations for DS-Lite January 2013
7.2. Informative References
[I-D.boucadair-softwire-dslite-v6only]
Boucadair, M., Jacquenet, C., Grimault, J., Kassi-Lahlou,
M., Levis, P., Cheng, D., and Y. Lee, "Deploying Dual-
Stack Lite in IPv6 Network",
draft-boucadair-softwire-dslite-v6only-01 (work in
progress), April 2011.
[I-D.ietf-intarea-nat-reveal-analysis]
Boucadair, M., Touch, J., Levis, P., and R. Penno,
"Analysis of Solution Candidates to Reveal a Host
Identifier (HOST_ID) in Shared Address Deployments",
draft-ietf-intarea-nat-reveal-analysis-04 (work in
progress), August 2012.
[I-D.ietf-pcp-base]
Wing, D., Cheshire, S., Boucadair, M., Penno, R., and P.
Selkirk, "Port Control Protocol (PCP)",
draft-ietf-pcp-base-29 (work in progress), November 2012.
[I-D.xu-behave-stateful-nat-standby]
Xu, X., Boucadair, M., Lee, Y., and G. Chen, "Redundancy
Requirements and Framework for Stateful Network Address
Translators (NAT)",
draft-xu-behave-stateful-nat-standby-06 (work in
progress), October 2010.
[RFC2473] Conta, A. and S. Deering, "Generic Packet Tunneling in
IPv6 Specification", RFC 2473, December 1998.
[RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
and W. Weiss, "An Architecture for Differentiated
Services", RFC 2475, December 1998.
[RFC2983] Black, D., "Differentiated Services and Tunnels",
RFC 2983, October 2000.
[RFC3022] Srisuresh, P. and K. Egevang, "Traditional IP Network
Address Translator (Traditional NAT)", RFC 3022,
January 2001.
[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Protocol Modifications for the DNS Security
Extensions", RFC 4035, March 2005.
[RFC5245] Rosenberg, J., "Interactive Connectivity Establishment
(ICE): A Protocol for Network Address Translator (NAT)
Lee, et al. Expires July 21, 2013 [Page 13]
Internet-Draft Deployment Considerations for DS-Lite January 2013
Traversal for Offer/Answer Protocols", RFC 5245,
April 2010.
[RFC5625] Bellis, R., "DNS Proxy Implementation Guidelines",
BCP 152, RFC 5625, August 2009.
[RFC5985] Barnes, M., "HTTP-Enabled Location Delivery (HELD)",
RFC 5985, September 2010.
[RFC6269] Ford, M., Boucadair, M., Durand, A., Levis, P., and P.
Roberts, "Issues with IP Address Sharing", RFC 6269,
June 2011.
[RFC6280] Barnes, R., Lepinski, M., Cooper, A., Morris, J.,
Tschofenig, H., and H. Schulzrinne, "An Architecture for
Location and Location Privacy in Internet Applications",
BCP 160, RFC 6280, July 2011.
[RFC6302] Durand, A., Gashinsky, I., Lee, D., and S. Sheppard,
"Logging Recommendations for Internet-Facing Servers",
BCP 162, RFC 6302, June 2011.
Authors' Addresses
Yiu L. Lee
Comcast
One Comcast Center
Philadelphia, PA 19103
U.S.A.
Email: yiu_lee@cable.comcast.com
URI: http://www.comcast.com
Roberta Maglione
Telecom Italia
Via Reiss Romoli 274
Torino 10148
Italy
Email: roberta.maglione@telecomitalia.it
URI:
Lee, et al. Expires July 21, 2013 [Page 14]
Internet-Draft Deployment Considerations for DS-Lite January 2013
Carl Williams
MCSR Labs
U.S.A.
Email: carlw@mcsr-labs.org
Christian Jacquenet
France Telecom
Rennes
France
Email: christian.jacquenet@orange.com
Mohamed Boucadair
France Telecom
Rennes
France
Email: mohamed.boucadair@orange.com
Lee, et al. Expires July 21, 2013 [Page 15]
