Operation Manual – IPv6H3C S5500-EI Series Ethernet Switches Chapter 1 IPv6 Basics Configuration1-3z Stateless address configuration means that a host automatically configures anIPv6 address and related information on basis of its own link-layer address and theprefix information advertised by a router.In addition, a host can generate a link-local address on basis of its own link-layeraddress and the default prefix (FE80::/64) to communicate with other hosts on the link.V. Built-in securityIPv6 uses IPSec as its standard extension header to provide end-to-end security. Thisfeature provides a standard for network security solutions and improves theinteroperability between different IPv6 applications.VI. QoS supportThe Flow Label field in the IPv6 header allows the device to label packets in a flow andprovide special handling for these packets.VII. Enhanced neighbor discovery mechanismThe IPv6 neighbor discovery protocol is implemented through a group of InternetControl Message Protocol Version 6 (ICMPv6) messages that manages the informationexchange between neighbor nodes on the same link. The group of ICMPv6 messagestakes the place of Address Resolution Protocol (ARP) message, Internet ControlMessage Protocol version 4 (ICMPv4) router discovery message, and ICMPv4redirection message to provide a series of other functions.VIII. Flexible extension headersIPv6 cancels the Options field in IPv4 packets but introduces multiple extensionheaders. In this way, IPv6 enhances the flexibility greatly to provide scalability for IPwhile improving the handling efficiency. The Options field in IPv4 packets contains 40bytes at most, while the size of IPv6 extension headers is restricted by that of IPv6packets.1.1.2 Introduction to IPv6 AddressI. IPv6 address formatAn IPv6 address is represented as a series of 16-bit hexadecimals, separated bycolons. An IPv6 address is divided into eight groups, and the 16 bits of each group arerepresented by four hexadecimal numbers which are separated by colons, for example,2001:0000:130F:0000:0000:09C0:876A:130B.To simplify the representation of IPv6 addresses, zeros in IPv6 addresses can behandled as follows:
