The defining feature of IPv6 is increased address space in comparison to IPv4. IPv6 also improves Internet capabilities in numerous areas, as outlined in this section.
IP address size increases from 32 bits in IPv4 to 128 bits in IPv6, to support more levels of addressing hierarchy. In addition, IPv6 provides many more addressable IPv6 systems. For more information, see IPv6 Addressing Overview.
The IPv6 Neighbor Discovery (ND) protocol facilitates the autoconfiguration of IPv6 addresses. Autoconfiguration is the ability of an IPv6 host to automatically generate its own IPv6 address, which makes address administration easier and less time-consuming. For more information, see IPv6 Address Autoconfiguration.
The Neighbor Discovery protocol corresponds to a combination of these IPv4 protocols: Address Resolution Protocol (ARP), Internet Control Message Protocol (ICMP), Router Discovery (RDISC), and ICMP Redirect. IPv6 routers use Neighbor Discovery to advertise the IPv6 site prefix. IPv6 hosts use Neighbor Discovery for various purposes, which include soliciting the prefix from an IPv6 router. For more information, see IPv6 Neighbor Discovery Protocol Overview.
The IPv6 header format either drops or makes optional certain IPv4 header fields. This change keeps the bandwidth cost of the IPv6 header as low as possible, despite the increased address size. Even though IPv6 addresses are four times longer than IPv4 addresses, the IPv6 header is only twice the size of the IPv4 header.
Changes in the way IP header options are encoded allow for more efficient forwarding. Also, IPv6 options have less stringent limits on their length. The changes provide greater flexibility for introducing new options in the future.
Many critical Solaris network services recognize and support IPv6 addresses, for example:
Name services, such as DNS, LDAP, and NIS. For more information on IPv6 support by these name services, see System Administration Guide: Naming and Directory Services (DNS, NIS, and LDAP).
Authentication and privacy applications, such as IP Security Architecture (IPsec) and Internet Key Exchange (IKE). For more information, see Part III, IP Security.
Differentiated services, as provided by IP Quality of Service (IPQoS). For more information, see Part IV, IP Quality of Service (IPQoS).
Failover detection, as provided by IP network multipathing (IPMP). For more information, see Failure and Repair Detection in IPMP in System Administration Guide: Network Interfaces and Network Virtualization.
In addition to this Part, you can obtain information about IPv6 from the sources that are listed in the following sections.
Many RFCs are available regarding IPv6. The following table lists the major IPv6 articles and their Internet Engineering Task Force (IETF) web locations as of this writing.
Table 3–1 IPv6–Related RFCs and Internet Drafts
RFC or Internet Draft |
Subject |
Location |
---|---|---|
RFC 2461, Neighbor Discovery for IP Version 6 (IPv6) |
Describes the features and functions of IPv6 Neighbor Discovery protocol | |
RFC 3306, Unicast—Prefix—Based IPv6 Multicast Addresses |
Describes the format and types of IPv6 multicast addresses | |
RFC 3484: Default Address Selection for Internet Protocol version 6 (IPv6) |
Describes the algorithms used in IPv6 default address selection | |
RFC 3513, Internet Protocol version 6 (IPv6) Addressing Architecture |
Contains complete details about the types of IPv6 addresses and includes many examples | |
RFC 3587, IPv6 Global Unicast Address Format |
Defines the standard format for IPv6 unicast addresses |
The following web sites provide useful information about IPv6.
Table 3–2 IPv6–Related Web Sites
Web Site |
Description |
Location |
---|---|---|
IPv6 Forum |
Links to IPv6–related presentations, events, classes, and implementations worldwide are available from this society's web site | |
Internet Educational Task Force IPv6 Working Group |
Links to all relevant IPv6 RFCs and Internet Drafts are on the home page of this IETF working group |