Technical data

IPv6

Internet Protocol Version 6 (IPv6), as defined in RFC 2460, is the replacement

Network layer protocol for the Internet and is designed to replace Internet Protocol

Version 4 (IPv4). IPv6 also changes the structure of the Internet architecture.

This does not mean that you have to deploy IPv6 all at once across your network;

rather, you can make the change in stages because IPv6 and IPv4 were designed

to interoperate. This chapter provides guidelines for deployment, deployment

scenarios, and checklists for you to consult before you configure a single system

or your entire network.

Things to Consider

Before implementing IPv6 into your network, consider the following:

•IsmysystempartofanIPv6network?

• What is my internet/intranet scenario?

9.1 Understanding IPv6

The following is a summary of IPv6 features:

•Addressing

The IPv6 address is 128 bits in length (compared with the 32-bit IPv4 address)

and uses a new text representation format. In addition, there are three types of

IPv6 addresses: unicast, anycast, and multicast. The unicast address consists

of an address prefix and a 64-bit interface identifier. For information about

IPv6 addresses, refer to the Compaq TCP/IP Services for OpenVMS Guide to

IPv6 manual and to RFC 2373.

• Neighbor discovery

Neighbor discovery is a mechanism by which IPv6 nodes on the same link

discover each other’s presence, determine each other’s link-local addresses, find

routers, and maintain reachability information about paths to active neighbors

and remote destinations. For more information, refer to RFC 2461.

• Stateless address autoconfiguration

The process by which IPv6 nodes listen for router advertisement packets

from routers and learn IPv6 address prefixes. The node creates IPv6 unicast

addresses by combining the prefix with a datalink-specific interface identifier

that is typically derived from the datalink address of the interface. The

OpenVMS operating system performs this process automatically. For more

information, refer to RFC 2462.

9.1.1 Mobile IPv6

TCP/IP Services enables an OpenVMS node to operate as a mobile IPv6

correspondent node as defined in the Internet draft “Mobility Support in IPv6”

(David B. Johnson and Charles Perkins). For more information about this proposed

standard, refer to:

http://www.ietf.org/ietf/1id-abstracts.txt

IPv6 9–1