HP HP-UX IPv6 White Paper

HP-UX IPv6 Transition Mechanisms

White Paper

Table of Contents

Table of Contents................................................................................................................... 1

1. Executive Summary............................................................................................................................... 2

2. Overview .............................................................................................................................................. 3

3. Terminology .......................................................................................................................................... 3

4. Dual Stack ............................................................................................................................................ 3

5. Tunneling .............................................................................................................................................. 4

5.1 Host-to-Host..................................................................................................................... 4

5.2 Router-to-Router................................................................................................................ 5

5.3 Host-to-Router and Router-to-Host........................................................................................ 5

6. 6to4 ...................................................................................................................................................... 6

7. Transition from IPv4 to IPv6 .................................................................................................................. 7

8. Deployment Scenario ........................................................................................................................... 8

8.1 Access to Payroll Application in the Main Office ................................................................. 9

8.2 Access to Accounting Application in Branch Office A .......................................................... 9

9. Related Documents ............................................................................................................................. 10

1. Executive Summary

The Internet has evolved as a critical business communication medium; the current Internet Protocol (IPv4), which has been amazingly resilient so far, will not be able to support the continuous growth of the Internet indefinitely. The new emerging markets of nomadic personal computing devices, IP enabled devices and networked home entertainment require unique addressing, improved mobility and security. IPv4, though retrofitted to meet some of the needs, is fast reaching its limit.

The Internet Engineering Task Force (IETF) has designed IPv6, the successor to IPv4, to meet the growing demands of the Internet and Enterprise Networks. IPv6 was designed to improve upon the scalability, security, mobility, ease of configuration and management capabilities of IPv4. Some of the key advantages of IPv6 are:

• Expanded Routing and Addressing: IPv6 increases the address size from 32 bits to 128 bits, thus exponentially increasing the number of available unique addresses. It also supports multiple levels of addressing hierarchy.

• Mandatory Security: Security extension headers are part of the base IPv6 protocol and hence a mandatory part of every IPv6 implementation. Together with the increased address space, it allows to provide end-to-end security.

• Natural Mobility support: The improved option support in IPv6, together with stateless address autoconfiguration, routing headers, security headers and a new type of address called the “anycast” address contribute to the natural design of mobility for IPv6 nodes.

• Integrated QoS support: The Flow Label and Traffic Class fields are part of the IPv6 header and can be used for prioritization and reservation of network traffic.

Even though IPv6 provides many improvements over IPv4, IPv6 adoption is going to be gradual due to the vast installed base of IPv4. The Internet is too large for any kind of controlled upgrade. IPv6 will have to be deployed in a highly diffusive and incremental manner with minor interdependencies. The newly deployed IPv6 nodes should also be able to interoperate with existing IPv4 nodes. The IETF has designed many transition mechanisms to help achieve these goals.

This document describes the transition mechanisms currently supported by HP-UX and how these mechanisms can be used to deploy IPv6 with no impact to the existing IPv4 infrastructure.

2. Overview

Large-scale migration to any new technology is challenging and time consuming. IPv6 is no exception; its deployment is expected to be gradual. As IPv6 is being deployed, there will be a lengthy transition period during which IPv4 and IPv6 protocols will need to coexist. The IETF developed a number of transition mechanisms that will facilitate IPv6 deployment without impacting the existing installed base. The main goals of these transition mechanisms are to allow newly deployed IPv6 nodes to interoperate with existing IPv4 nodes and allow isolated IPv6 nodes to communicate with each other using the existing IPv4 infrastructure.

HP-UX (11iv1, 11iv2) supports the following transition mechanisms:

• Dual stack

• Tunneling

• 6to4

The transition mechanisms dual stack and tunneling are specified in [3] and 6to4 is specified in [4].

3. Terminology

IPv4-only node: A host or router that supports only IPv4. An IPv4-only node does not understand

IPv6. The installed base of IPv4 hosts and routers existing before the transition begins are IPv4-only nodes.

IPv6/IPv4 node: A host or router that supports both IPv4 and IPv6. Those nodes are also called dual stack nodes.

IPv6-only node: A host or router that supports IPv6 only, and does not support IPv4.

IPv6 node: Any host or router that supports IPv6. IPv6/IPv4 and IPv6-only nodes are both IPv6 nodes.

IPv4 node: Any host or router that supports IPv4. IPv6/IPv4 and IPv4-only nodes are both IPv4 nodes.

4. Dual Stack

Dual stack (or dual IP layer) is a technique that provides complete support for both IPv4 and IPv6 protocols in a single node, thus allowing the node to support both existing IPv4 applications and new IPv6 applications.

Application layer

A pp lication la ye r

Transp ort la yer (T C P/U D P/..)

T ransp ort la yer (T C P/U D P/..)

IPv 6 IPv 4

Link layer

Figure 1: Du al-stack

Figure 1: Dual-stack

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