46 IPV6 BASICS CONFIGURATIONWhen configuring IPv6 basics, go to these sections for information you areinterested in:■ “IPv6 Overview” on page 655■ “IPv6 Basics Configuration Task List” on page 664■ “Configuring Basic IPv6 Functions” on page 665■ “Configuring IPv6 NDP” on page 666■ “Configuring PMTU Discovery” on page 670■ “Configuring IPv6 TCP Properties” on page 671■ “Configuring IPv6 FIB-Based Forwarding” on page 671■ “Configuring ICMPv6 Packet Sending” on page 672■ “Configuring IPv6 DNS” on page 673■ “Displaying and Maintaining IPv6 Basics Configuration” on page 674■ “IPv6 Configuration Example” on page 675■ “Troubleshooting IPv6 Basics Configuration” on page 678IPv6 Overview Internet protocol version 6 (IPv6), also called IP next generation (IPng), wasdesigned by the Internet Engineering Task Force (IETF) as the successor to Internetprotocol version 4 (IPv4). The significant difference between IPv6 and IPv4 is thatIPv6 increases the IP address size from 32 bits to 128 bits.This section covers the following:■ “IPv6 Features” on page 655■ “Introduction to IPv6 Address” on page 657■ “Introduction to IPv6 Neighbor Discovery Protocol” on page 659■ “IPv6 PMTU Discovery” on page 663■ “Introduction to IPv6 DNS” on page 664■ “Protocols and Standards” on page 664IPv6 Features Header format simplificationIPv6 cuts down some IPv4 header fields or move them to the IPv6 extensionheaders to reduce the length of the basic IPv6 header. IPv6 uses the basic headerwith a fixed length, thus making IPv6 packet handling simple and improvingforwarding efficiency. Although the IPv6 address size is four times that of IPv4
