TCP/IP Explained
An easy to understand, comprehensive, and high-level introduction to TCP/IP.
TABLE OF CONTENTS TCP/IP Explained
Chapter 24: IP VERSION 6
Overview
If we have to look for limitations in the Internet Protocol Suite, one must surely be addressing. In today's networks the old 32 bit address is most woefully inadequate and urgently needs to be replaced by something that will cope with the explosive growth that is expected to continue. So what will it be?
The current thinking is that version 4 of IP (the current version, and that described in Chapter 4 and Chapter 5) should be replaced by version 6, or IP Next Generation (IPng) as it is sometimes called. But what are the implications of this and how will it operate in mixed V4/V6 environments? This chapter then details the IP Version 6 header, it's extensions and the changes required to ICMP.
24.1 IP Version 6 Enhancements
IP version 6 provides significant enhancements over the current, version 4, implementation. RFC 1883 defines these improvements in the following 5 areas:
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Extended Addressing capability
Version 6 increases the IP address size from 32 to 128 bits. This address is then split into a greater number of hierarchical levels than merely Network ID, possible Subnet ID, and Host ID. In addition, Multicast routing is improved with a scope field and a new address type, the so-called anycast address. This new address is being defined so that a packet can be sent to any one of a group of nodes.
Finally, there is no broadcast address for version 6. The concept of broadcasting with IP is now being superseded...
Copyright Butterworth-Heinemann 1997 under license agreement with Books24x7
