Internet Engineering Task Force G. Chen Internet-Draft Z. Cao Intended status: Informational China Mobile Expires: January 5, 2013 C. Byrne T-Mobile USA C. Xie China Telecom D. Binet France Telecom July 04, 2012 NAT64 Operational Experiences draft-chen-v6ops-nat64-experience-02 Abstract This document summarizes some stateful NAT64 deployment scenarios and operational experiences for NAT64-CGN and NAT64-CE. 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 January 5, 2013. Copyright Notice Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must Chen, et al. Expires January 5, 2013 [Page 1] Internet-Draft NAT64 Experience July 2012 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. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. NAT64-CGN Deployment Experiences . . . . . . . . . . . . . . . 4 3.1. NAT64-CGN Networking . . . . . . . . . . . . . . . . . . . 5 3.2. High Availability Consideration . . . . . . . . . . . . . 6 3.3. Traceability . . . . . . . . . . . . . . . . . . . . . . . 6 3.4. Quality of Experience . . . . . . . . . . . . . . . . . . 7 3.5. Load Balance . . . . . . . . . . . . . . . . . . . . . . . 8 3.6. MTU Consideration . . . . . . . . . . . . . . . . . . . . 8 4. NAT64-CE Deployment Experiences . . . . . . . . . . . . . . . 8 4.1. NAT64-CE Networking . . . . . . . . . . . . . . . . . . . 9 4.2. Anti-DDoS/SYN Flood . . . . . . . . . . . . . . . . . . . 10 4.3. User Behavior Analysis . . . . . . . . . . . . . . . . . . 10 4.4. DNS Resolving . . . . . . . . . . . . . . . . . . . . . . 10 4.5. Load Balance . . . . . . . . . . . . . . . . . . . . . . . 10 4.6. MTU Consideration . . . . . . . . . . . . . . . . . . . . 11 5. Security Considerations . . . . . . . . . . . . . . . . . . . 11 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11 8. Additional Author List . . . . . . . . . . . . . . . . . . . . 11 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12 9.1. Normative References . . . . . . . . . . . . . . . . . . . 12 9.2. Informative References . . . . . . . . . . . . . . . . . . 13 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14 Chen, et al. Expires January 5, 2013 [Page 2] Internet-Draft NAT64 Experience July 2012 1. Introduction With fast developments of global Internet, the demands for IP addresses are rapidly increasing. IANA announced that the global IPv4 address pool has been exhausted on February 3, 2011. IPv6 is the only sustainable and perennial solution for numbering nodes on the Internet. Network operators have to accelerate the process of deploying IPv6 networks in order to meet the numbering needs of expanding internet without available IPv4 addresses. As IPv6 deployments progress, IPv6 will coexist with IPv4. The Internet will include nodes that are IPv4-only, IPv6-only, and nodes that are dual-stack with IPv4 and IPv6. As IPv6 deployment progresses it may be simpler for operators to employ a single-version network, since deploying both IPv4 and IPv6 protocol in parallel would costs more than managing IPv6-only network. In a dual stack architecture, operators have to maintain double management interfaces and operational support system . Moreover, some additional efforts should be paid for troubleshooting. On the other hand, IPv6 could simplify the network provisioning. Some justification has described in [I-D.ietf-v6ops-464xlat], IPv6- only network is likely superior for operators to employ. In mobile contexts, it could enable single IPv6 PDP, which eliminates significant network cost caused by doubling the PDP count on a mass of legacy mobile terminals. In broadband network, it could help to scale edge network growth decoupled with IPv4 limitation. With network transition, a significant part of network rely on IPv4 stack for a long time. The interconnection between IPv4-only nodes and IPv6-only nodes is a critical capability. Given that widespread dual-stack deployments have not been materialized over the last 10 years, it is translation mechanism based on obvious that NAT64[RFC6146] function will be a key element of the going-forward internet infrastructure. [RFC6036] reported at least 30% operators plan to run some kind of translator (presumably NAT64/DNS64). Operators would expect to get more NAT64 deployment experiences. A very good example as [RFC6586] documented show the benefits for operational communities. Compared to it, this document is more specific on NAT64 network planning. Regarding the IPv4/IPv6 translation, [RFC6144] has described a framework enabling networks make interworking possible between IPv4- only and IPv6-only networks. There are three scenarios "An IPv6 Network to the IPv4 Internet", "The IPv6 Internet to an IPv4 Network" and "An IPv6 Network to an IPv4 Network" where NAT64 function is relevant. Since the scenario of "The IPv6 Internet to the IPv4 Chen, et al. Expires January 5, 2013 [Page 3] Internet-Draft NAT64 Experience July 2012 Internet" seems the ideal case for inter-network translation technology, this document has focused on the three cases and categorized different NAT64 location and usages, depending if the NAT64 is located in a NAT64-CGN and NAT64-CE. Therein, NAT64-CGN is corresponding to the scenario "IPv6 Network to IPv4 Internet". NAT64-CE is for "IPv6 Internet to IPv4 Network" and "IPv6 Network to IPv4 Network" respectively. Based on different NAT64 modes, different considerations have been elaborated for ISPs to facilitate NAT64 deployments. The purpose of this document is to summarize deployment experience of several operators and content providers regarding NAT64. The reader of this document can get the information for their possible deployment of NAT64 in future. Whether the audiences take the experience as their deployment guidance is up to them, not the purpose of this document. 2. Terminology The terms of NAT-CGN/CE is to be understood as a topological qualifier to indicate different features for NAT64 deployment. NAT64-CGN: A NAT64-CGN is placed in ISP network and managed by an administrative entity, e.g. operators. From an administrator view, NAT64-CGN usually forwards outbound traffic heading to IPv4 realm. IPv4 services in large scale could leverage the NAT64- CGN node to serves ISP's subscribers with IPv6-enable services. ISP as an administrative entity takes full control on IPv6 sides but has limited or no control on IPv4 sides. Therefore, ISP should accommodate the predominant IPv4 networks and guarantee compatibilities for IPv4 services in wild. NAT64-CE: A NAT64-CE is placed at the edge of customer network, e.g. a network operated by an enterprise or Internet data center. NAT64-CE makes IPv4 services in small/medium scale accessible for the IPv6 only users. An administrative entity usually operates a IPv4 network and take IPv6 access as a common infrastructure. Since the services have been run at customer network scale, NAT64-CE should only take care of particular types. 3. NAT64-CGN Deployment Experiences The NAT64-CGN Scenario is depicted in Figure 1 Chen, et al. Expires January 5, 2013 [Page 4] Internet-Draft NAT64 Experience July 2012 ----------- ---------- // \\ // \\ / \ / +----+ \ | |XLAT| | | An IPv6 +----+ The IPv4 | | Network +----+ Internet | XLAT: IPv6/IPv4 | |DNS | | Translator \ +----+ / DNS: DNS64 \\ // \ / --------- \\ // ----------- ====> Figure 1: NAT64-CGN Scenario: IPv6 Network to IPv4 Internet 3.1. NAT64-CGN Networking NAT64-CGN case is focusing on connecting IPv6-only users with IPv4 Internet. NAT64 performs protocol translation from an IPv6 packet header to an IPv4 packet header and vice versa is performed according to the Stateful NAT64 [RFC6146]. Address translation maps IPv6 addresses to IPv4 addresses and vice versa. Given that all connections to the IPv4 Internet from IPv6-only clients must traverse the NAT64, the NAT64 should be located close to the IPv4 peering points to reduce unnecessary backhaul costs and latency. It is advantageous for troubleshooting and traffic engineering to maintain the IPv6 traffic native for as long as possible within an access network and only translate at the network border.Traffic patterns as well as techno-economics studies have to be carried out in order to define the optimized location for the NAT64 function. Technical considerations, as detailed in this section have also to be considered for location selection. Coming to a real practice in broadband access network, NAT64 functionalities could be located on BNG(Broadband Network Gateway) or Core Router depending on scale of IPv6-enable network. Considering mobile networks, various possibilities can be envisaged to deploy some NAT64 functions. Whatever the retained option, the NAT64 function will be deployed beyond the GGSN(Gateway GPRS Support Node) or PDN-GW(Public Data Network-Gateway), i.e. first IP nodes in current mobile architectures. From implementation views, NAT64 functionalities could be served by either a dedicated GW or an existing GW integrated with NAT64 functionality. In standalone NAT64, NAT64-CGN is placed in a side of Chen, et al. Expires January 5, 2013 [Page 5] Internet-Draft NAT64 Experience July 2012 BNG or CR. The deployment has few impacts to a given network, which results in a low OPEX. On the other side, an embedded NAT64 is integrated with existing GW, it requires relative lower investment, i.e. lower CAPEX. However, capacities of existing GW would be restricted by the inserted functionality. It likely requires a new round of network planning, which would cause high OPEX. In a mobile context, NAT64 function can be co-located with GGSN/PDN-GW or it can be embedded in existing FW/NAT44 already deployed or the function can be collocated in existing routers. Whatever the solution retained for the co-location option, impacts on existing services and legal obligations have to be assessed. More discussion can be found at following sub-sections. The different deployment modes would correspond to specific use cases, in which ISP should consider different perspectives, e.g. traffic model, investment, network evolution, etc. 3.2. High Availability Consideration High Availability (HA) is a major requirement for every service and network service. Two mechanisms are likely to be used to achieve high reliability, i.e. cold-standby and hot-standby. Cold-standby has synchronized configuration and mechanism to failover traffic between the hot and cold systems such as VRRP [RFC5798] . Unlike hot-standby, cold- standby does not synchronize NAT64 session state. This makes cold- stanby less resource intensive and generally simpler, but it requires clients to re-establish sessions when a fail-over occurs. Hot-stanby has all the features of cold-standby but must also synchronize the binding information base (BIB). Considering the most common Internet traffic type is short lived sessions, hot-standby does not offer much benefit unless long lived sessions are common and the cost is justified. 3.3. Traceability Traceablility is required in many cases to identify an attacker or a host that launchs malicious attacks and/or for various other purposes, such as accounting requirements. NAT64 devices are required to log events like creation and deletion of translations and information about the occupied resources. There are two different demands for traceability,i.e. online or offline. o Regarding the Online requirements, XFF (X-Forwarded-For) [I-D.petersson-forwarded-for]would be a candidate, it appends IPv6 address of subscribers to HTTP headers which is passed on to WEB servers, and the querier server can lookup radius servers for the Chen, et al. Expires January 5, 2013 [Page 6] Internet-Draft NAT64 Experience July 2012 target subscribers based on IPv6 addresses included in XFF HTTP headers. Some other solutions, as described in [I-D.ietf-intarea-nat-reveal-analysis].NAT64-CGN could also deliver NAT64 session (BIB and STE) to Radius server by some extent of radius protocol extension. That is an alternative solution for online traceability, but high performance is required on Radius servers . o For off-line traceability, syslog might be a good choice. [RFC6269] indicates address sharing solutions must record and store information for specific period. Stateful NAT64 is supposed to manage one mapping per session. That would raise a challenge for storage and data processing. In order to mitigate the issue, [I-D.donley-behave-deterministic-cgn]proposed to pre-allocated a group of ports for each specific IPv6 host. A trade-off among address multiplexing efficiency, port randomization security[RFC6056] and logging storage compression should be considered during the planning. A hybrid mode combining deterministic and dynamic port assignment was recommended regarding the uncertainty of user traffic mode. 3.4. Quality of Experience NAT64 is providing some translation capability between IPv6 and IPv4 end-nodes. In order to provide the reachability between two IP address families, NAT64-CGN has to implement the appropriate ALGs, e.g. FTP-ALG[RFC6384], RSTP-ALG, H.323-ALG,etc. It should be noted that such ALG implementation may impact the performance on a NAT64 box in some extent. Therefore, ISPs as well as content providers should avoid ALG requisition, when they design behaviors of the client and server. They have to make sure that contents are reachable thanks to native IPv6 connectivity. At the same time, it is also important to remind customers that IPv6 end-to-end does not required ALGs and therefore that provides the best experience. The service experiences also should be optimized regarding stateful NAT process. To be specific, session status normally is managed by a static lifetime cycle. In some cases, NAT resource maybe suffered from significant inactive users. NAT and beyond customers can also suffer from service degradation because of number of ports consummation by other subscribers using the same NAT64 device. A flexible NAT session control is desirable to resolve the issues. PCP[I-D.ietf-pcp-base] could be a candidate to provide such capability. In the case, NAT64-CGN should integrate with PCP server, depending on which available IPv4 address/Port could be assigned to PCP client through PCP MAP/PEER mode. Such abilities should also be considered to upgrade user experiences, e.g. assigning different sizes of port ranges for different subscribers.Such mechanism is also Chen, et al. Expires January 5, 2013 [Page 7] Internet-Draft NAT64 Experience July 2012 helpful to minimize terminal battery consumption reducing the number of keepalive messages to be sent by terminal devices. 3.5. Load Balance Load balance is an essential ability to avoid the issue of single point of failure and add the feature of linear scalability. It is important to achieve load balancing between these different devices considering that deployment of multiple NAT64 devices is required to achieve some service continuity and some QoE for the customers. [I-D.zhang-behave-nat64-load-balancing] discusses several ways of achieving NAT64 load balancing, including anycast based policy and prefix64 selection based policy, either implemented via DNS64 or Prefix64 assignments. 3.6. MTU Consideration IPv6 requires that every link in the internet have an MTU of 1280 octets or greater[RFC2460]. However, in case of NAT64 function deployment some IPv4 link will be used on communication path and originating IPv6 node may receive an ICMP Packet Too Big message reporting a Next-Hop MTU less than 1280. That would result the IPv6 allows packets to contain a fragment header, without the packet being actually fragmented into multiple pieces. [I-D.ietf-6man-ipv6-atomic-fragments] discusses how this could situation could be exploited by an attacker to perform fragmentation- based attacks, and also proposes an improved handling of such packets. It required enhancements on protocol level, which might imply potential upgrade/modifications on behaviors to deployed nodes. Another candidate approach avoding this issue is to configure IPv4 MTU>=1260 from operational perspectives. It would forbid the occurrence of PTB<1280. However, such operational consideration is hardly applied to a wild and legacy "IPv4 Internet". In this case, these issues are eliminated thanks to some specific operational actions 4. NAT64-CE Deployment Experiences The NAT64-CE Scenario is depicted in Figure 2 Chen, et al. Expires January 5, 2013 [Page 8] Internet-Draft NAT64 Experience July 2012 -------- // \\ ---------- / \ // \\ / +----+ \ | |XLAT| | | The IPv6 +----+ An IPv4 | | Internet +----+ Network | XLAT: IPv4/IPv6 | /Network |DNS | | Translator \ +----+ / DNS: DNS64 \ / \\ // \\ // ---------- -------- ====> Figure 2: NAT64-CE Scenario: IPv6 Internet/Network to IPv4 Network 4.1. NAT64-CE Networking More and more contents providers would like to use IPv6 to serve customers since it allows for the definition of new services without having to backward integrate into the NATs and address limitations of IPv4 networks, but they have to provide some IPv4 service continuity to their customers and that militates for NAT64 design. Cloud computing is growing, which requires millions of public addresses. IPv6 could provide a good opportunity to meet the deployment requirements by subsiding the location to a customer edge, e.g. Enterprise-GW and Data Center. On the other side, residential facilities is always going out of ISP control as far as devices connected to home networks are not under ISP responsibility. It's hard to guarantee positioned network device or installed applications are IPv6-capable and it is not possible to consider that all devices are IPv6 compliant. Thereby, NAT64 on CPE could easily help networks deployment and to rely on some IPv6-only connectivity from the ISP. One big challenge is NAT64-CE facing IPv6 Internet, on which a significant IPv6 users may connect to. When increasingly numerous users in IPv6 Internet access an IPv4 network, there will be not enough IPv4 addresses and/or ports to serve the mapping. One potential solution is to distribute NAT64-CE at separated CE domain. Each domain could reuse the IPv4 address defined in RFC1918 [RFC1918], which would expand IPv4 spaces by increasing reuse ratio of IPv4 address. Note: considering this challenge of NAT64, it is suggested that NAT64-CE is only deployed and used in the scenario for small scale content providers and residential network where the incoming connections from the IPv6 Internet is not too many to destroy the NAT64 functionalities. Chen, et al. Expires January 5, 2013 [Page 9] Internet-Draft NAT64 Experience July 2012 4.2. Anti-DDoS/SYN Flood For every incoming new connection from the IPv6 Internet, the NAT64-CE creates state and maps that connection to an internally- facing IPv4 address and port. An attacker can consume the resources of the NAT64-CE device by sending an excessive number of connection attempts. Without Anti-DDoS mechanism, the NAT64 is exposed to attacks from the IPv6 Internet which will greatly influence the user experience. Essentially, there are strong demands to have thorough security mechanism to prevent malicious invasion in NAT64-CE scenario. With service provisioning, potential safety hazard could also deteriorate service quality. For example, DDoS will severely degrade web performance. Security domain division is necessary in this case, especially for NAT64-CE in enterprise network. One practices in some ICP is place a L3 load balancer with capable of 10G line rate DDoS defense, like SYN Flood with SYN PROXY-COOKIE. Load Balancer could not only serve for optimization of traffic distribution, but also take filtering helping enhanment of security. 4.3. User Behavior Analysis The mapping information on the NAT64-CE is valuable for those who deploy it. Owners or operators of NAT64-CE could use the mapping and logging information for use behavior and preference analysis, and acurate advertisement delivery. Different ways of achieving user analysis may be applied. The NAT64-CE owner can either synchronize the mapping information with its local analysis engine or deploy dedicated address mapping rules on the CE so that the orginal address information could be kept. 4.4. DNS Resolving In the case of NAT64-CE, it is recommended to follow the recommendations in [RFC6144]. There is no need for the DNS to synthesize AAAA from A records, since static AAAA records can be registered in the regular DNS to represent these IPv4-only hosts. How to design the FQDN for the IPv6 service is out-of-scope of this document. 4.5. Load Balance Load balance on NAT64-CE was twofold. First off, traffic should be balanced among multiple NAT64-CE devices, which has identical requirement with NAT64-CGN. One point should be noticed that a synthetic AAAA records may be added directly in authoritative DNS. The load balance based on DNS64 may not work in those cases. Secondly, NAT64-CE could also serve traffic distribution for IPv4 backend servers. There are also some ways of load balance for the Chen, et al. Expires January 5, 2013 [Page 10] Internet-Draft NAT64 Experience July 2012 cases , where the user placed load balancer with NAT66 functionalities before the NAT64. 4.6. MTU Consideration As compared to the MTU consideration in NAT64-CGN, MTU of IPv4 network are strongly recommeded to set more than 1260. Since a IPv4 network normally operated by a particular entity, it could take advantages of administrative ways to easily get rid of fragmentation risks discussed in [I-D.ietf-6man-ipv6-atomic-fragments]. 5. Security Considerations This document presents the deployment experiences of NAT64 in CGN and CE scenario, some security considerations have been considered regarding to specific NAT64 mode in section 2 and 3. In general, RFC 6146[RFC6146] provides TCP-tracking, Endpoint-dependent filtering mechanisms to protect NAT64 from DDOS. In NAT64-CGN cases, ISP also could adopt uRPF and black/white-list to enhance the security by specifying access policies. for example, NAT64-CGN should forbid establish NAT64 BIB for incoming IPv6 packets if URPF (Strict or Loose mode) check does not pass or whose source IPv6 address is associated to black-lists. 6. IANA Considerations This memo includes no request to IANA. 7. Acknowledgements The authors would like to thank Jari Arkko, Dan Wing, Remi Despres, Fred Baker, Joel Jaeggli, Lee Howard and Iljitsch van Beijnum for their helpful comments. Many thanks to Wesley George and Satoru Matsushima for their reviews. 8. Additional Author List The following are extended authors who contributed to the effort: Chen, et al. Expires January 5, 2013 [Page 11] Internet-Draft NAT64 Experience July 2012 Qiong Sun China Telecom Room 708, No.118, Xizhimennei Street Beijing 100035 P.R.China Phone: +86-10-58552936 Email: sunqiong@ctbri.com.cn QiBo Niu ZTE 50,RuanJian Road. YuHua District, Nan Jing 210012 P.R.China Email: niu.qibo@zte.com.cn 9. References 9.1. Normative References [I-D.ietf-pcp-base] Wing, D., Cheshire, S., Boucadair, M., Penno, R., and P. Selkirk, "Port Control Protocol (PCP)", draft-ietf-pcp-base-26 (work in progress), June 2012. [RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and E. Lear, "Address Allocation for Private Internets", BCP 5, RFC 1918, February 1996. [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998. [RFC5798] Nadas, S., "Virtual Router Redundancy Protocol (VRRP) Version 3 for IPv4 and IPv6", RFC 5798, March 2010. [RFC6144] Baker, F., Li, X., Bao, C., and K. Yin, "Framework for IPv4/IPv6 Translation", RFC 6144, April 2011. [RFC6146] Bagnulo, M., Matthews, P., and I. van Beijnum, "Stateful NAT64: Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers", RFC 6146, April 2011. [RFC6384] van Beijnum, I., "An FTP Application Layer Gateway (ALG) for IPv6-to-IPv4 Translation", RFC 6384, October 2011. Chen, et al. Expires January 5, 2013 [Page 12] Internet-Draft NAT64 Experience July 2012 9.2. Informative References [I-D.donley-behave-deterministic-cgn] Donley, C., Grundemann, C., Sarawat, V., and K. Sundaresan, "Deterministic Address Mapping to Reduce Logging in Carrier Grade NAT Deployments", draft-donley-behave-deterministic-cgn-03 (work in progress), June 2012. [I-D.ietf-6man-ipv6-atomic-fragments] Gont, F., "Processing of IPv6 "atomic" fragments", draft-ietf-6man-ipv6-atomic-fragments-00 (work in progress), February 2012. [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-02 (work in progress), April 2012. [I-D.ietf-v6ops-464xlat] Mawatari, M., Kawashima, M., and C. Byrne, "464XLAT: Combination of Stateful and Stateless Translation", draft-ietf-v6ops-464xlat-05 (work in progress), July 2012. [I-D.petersson-forwarded-for] Petersson, A. and M. Nilsson, "Forwarded HTTP Extension", draft-petersson-forwarded-for-02 (work in progress), November 2011. [I-D.zhang-behave-nat64-load-balancing] Zhang, D., Xu, X., and M. Boucadair, "Considerations on NAT64 Load-Balancing", draft-zhang-behave-nat64-load-balancing-03 (work in progress), July 2011. [RFC3924] Baker, F., Foster, B., and C. Sharp, "Cisco Architecture for Lawful Intercept in IP Networks", RFC 3924, October 2004. [RFC6036] Carpenter, B. and S. Jiang, "Emerging Service Provider Scenarios for IPv6 Deployment", RFC 6036, October 2010. [RFC6056] Larsen, M. and F. Gont, "Recommendations for Transport- Protocol Port Randomization", BCP 156, RFC 6056, January 2011. Chen, et al. Expires January 5, 2013 [Page 13] Internet-Draft NAT64 Experience July 2012 [RFC6269] Ford, M., Boucadair, M., Durand, A., Levis, P., and P. Roberts, "Issues with IP Address Sharing", RFC 6269, June 2011. [RFC6586] Arkko, J. and A. Keranen, "Experiences from an IPv6-Only Network", RFC 6586, April 2012. Authors' Addresses Gang Chen China Mobile 53A,Xibianmennei Ave., Xuanwu District, Beijing 100053 China Email: phdgang@gmail.com Zhen Cao China Mobile 53A,Xibianmennei Ave., Xuanwu District, Beijing 100053 China Email: caozhen@chinamobile.com Cameron Byrne T-Mobile USA Bellevue Washington 98105 USA Email: cameron.byrne@t-mobile.com Chongfeng Xie China Telecom Room 708 No.118, Xizhimenneidajie Beijing 100035 P.R.China Email: xiechf@ctbri.com.cn Chen, et al. Expires January 5, 2013 [Page 14] Internet-Draft NAT64 Experience July 2012 David Binet France Telecom Rennes 35000 France Email: david.binet@orange.com Chen, et al. Expires January 5, 2013 [Page 15]