CGN

This document specifies a solution for the delivery of IPv4 multicast services to IPv4 clients over an IPv6 multicast network. The solution relies upon a stateless IPv4-in-IPv6 encapsulation scheme and uses an IPv6 multicast distribution tree to deliver IPv4 multicast traffic. The solution is particularly useful for the delivery of multicast service offerings to customers serviced by Dual-Stack Lite (DS-Lite).

This document defines a Dynamic Host Configuration Protocol version 6 (DHCPv6) Option for multicast IPv4 service continuity solutions, which is used to carry the IPv6 prefixes to be used to build unicast and multicast IPv4-embedded IPv6 addresses.

This document defines three new RADIUS attributes. For devices that implement IP port ranges, these attributes are used to communicate with a RADIUS server in order to configure and report IP transport ports as well as mapping behavior for specific hosts. This mechanism can be used in various deployment scenarios such as Carrier-Grade NAT, IPv4/IPv6 translators, Provider WLAN gateway, etc. This document defines a mapping between some RADIUS attributes and IP Flow Information Export (IPFIX) Information Element identifiers.

This document clarifies and updates several requirements of RFCs 4787, 5382, and 5508 based on operational and development experience. The focus of this document is Network Address Translation from IPv4 to IPv4 (NAT44).

This document updates RFCs 4787, 5382, and 5508.

This memo defines a portion of the Management Information Base (MIB) for devices implementing the Network Address Translator (NAT) function. The new MIB module defined in this document, NATV2-MIB, is intended to replace module NAT-MIB (RFC 4008). NATV2-MIB is not backwards compatible with NAT-MIB, for reasons given in the text of this document. A companion document deprecates all objects in NAT-MIB. NATV2-MIB can be used for the monitoring of NAT instances on a device capable of NAT function. Compliance levels are defined for three application scenarios: basic NAT, pooled NAT, and carrier-grade NAT (CGN).

This document specifies a new Port Control Protocol (PCP) functional element: the PCP proxy. The PCP proxy relays PCP requests received from PCP clients to upstream PCP server(s). A typical deployment usage of this function is to help establish successful PCP communications for PCP clients that cannot be configured with the address of a PCP server located more than one hop away.

In some instances, Service Providers (SPs) have a legal logging requirement to be able to map a subscriber's inside address with the address used on the public Internet (e.g., for abuse response). Unfortunately, many logging solutions for Carrier-Grade NATs (CGNs) require active logging of dynamic translations. CGN port assignments are often per connection, but they could optionally use port ranges. Research indicates that per-connection logging is not scalable in many residential broadband services. This document suggests a way to manage CGN translations in such a way as to significantly reduce the amount of logging required while providing traceability for abuse response. IPv6 is, of course, the preferred solution. While deployment is in progress, SPs are forced by business imperatives to maintain support for IPv4. This note addresses the IPv4 part of the network when a CGN solution is in use.

This document focuses on the problems encountered when using dynamic DNS in address-sharing contexts (e.g., Dual-Stack Lite (DS-Lite) and Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers (NAT64)) during IPv6 transition. Both issues and possible solutions are documented in this memo.

This document specifies a framework to integrate a Network Address Translation (NAT) layer into an operator's network to function as a Carrier-Grade NAT (also known as CGN or Large-Scale NAT). The CGN infrastructure will often form a NAT444 environment as the subscriber home network will likely also maintain a subscriber-side NAT function. Exhaustion of the IPv4 address pool is a major driver compelling some operators to implement CGN. Although operators may wish to deploy IPv6 to strategically overcome IPv4 exhaustion, near- term needs may not be satisfied with an IPv6 deployment alone. This document provides a practical integration model that allows the CGN platform to be integrated into the network, meeting the connectivity needs of the subscriber while being mindful of not disrupting existing services and meeting the technical challenges that CGN brings. The model included in this document utilizes BGP/MPLS IP VPNs, which allow for virtual routing separation, helping ease the CGN's impact on the network. This document does not intend to defend the merits of CGN.

NAT444 is an IPv4 extension technology being considered by Service Providers as a means to continue offering IPv4 service to customers while transitioning to IPv6. This technology adds an extra Carrier- Grade NAT (CGN) in the Service Provider network, often resulting in two NATs. CableLabs, Time Warner Cable, and Rogers Communications independently tested the impacts of NAT444 on many popular Internet services using a variety of test scenarios, network topologies, and vendor equipment. This document identifies areas where adding a second layer of NAT disrupts the communication channel for common Internet applications. This document was updated to include the Dual-Stack Lite (DS-Lite) impacts also.

This document defines common requirements for Carrier-Grade NATs (CGNs). It updates RFC 4787.

This document describes the framework, messages, and procedures for the Diameter Network address and port translation Control Application. This Diameter application allows per-endpoint control of Network Address Translators and Network Address and Port Translators, which are added to networks to cope with IPv4 address space depletion. This Diameter application allows external devices to configure and manage a Network Address Translator device -- expanding the existing Diameter-based Authentication, Authorization, and Accounting (AAA) and policy control capabilities with a Network Address Translator and Network Address and Port Translator control component. These external devices can be network elements in the data plane such as a Network Access Server, or can be more centralized control plane devices such as AAA-servers. This Diameter application establishes a context to commonly identify and manage endpoints on a gateway or server and a Network Address Translator and Network Address and Port Translator device. This includes, for example, the control of the total number of Network Address Translator bindings allowed or the allocation of a specific Network Address Translator binding for a particular endpoint. In addition, it allows Network Address Translator devices to provide information relevant to accounting purposes. [STANDARDS-TRACK]

This document requests the allocation of an IPv4 /10 address block to be used as Shared Address Space to accommodate the needs of Carrier- Grade NAT (CGN) devices. It is anticipated that Service Providers will use this Shared Address Space to number the interfaces that connect CGN devices to Customer Premises Equipment (CPE).

Shared Address Space is distinct from RFC 1918 private address space because it is intended for use on Service Provider networks. However, it may be used in a manner similar to RFC 1918 private address space on routing equipment that is able to do address translation across router interfaces when the addresses are identical on two different interfaces. Details are provided in the text of this document.

This document details the allocation of an additional special-use IPv4 address block and updates RFC 5735. This memo documents an Internet Best Current Practice.

Global IPv6 deployment was slower than originally expected. As IPv4 address exhaustion approaches, IPv4 to IPv6 transition issues become more critical and less tractable. Host-based transition mechanisms used in dual-stack environments cannot meet all transition requirements. Most end users are not sufficiently expert to configure or maintain host-based transition mechanisms. Carrier-Grade NAT (CGN) devices with integrated transition mechanisms can reduce the operational changes required during the IPv4 to IPv6 migration or coexistence period.

This document proposes an incremental CGN approach for IPv6 transition. It can provide IPv6 access services for IPv6 hosts and IPv4 access services for IPv4 hosts while leaving much of a legacy ISP network unchanged during the initial stage of IPv4 to IPv6 migration. Unlike CGN alone, incremental CGN also supports and encourages smooth transition towards dual-stack or IPv6-only ISP networks. An integrated configurable CGN device and an adaptive home gateway (HG) device are described. Both are reusable during different transition phases, avoiding multiple upgrades. This enables IPv6 migration to be incrementally achieved according to real user requirements. This document is not an Internet Standards Track specification; it is published for informational purposes.