Information Technology Reference
In-Depth Information
Ta ble 9 - 8 summarizes IPv6 address schemes.
Ta b l e 9 - 8
IPv6 Address Autoconfiguration Scheme
Description
IPv6 Address
Configuration Scheme
Host sends a neighbor-solicitation message that includes the
target IPv6 address that begins with FE80::.
Stateless link-local
Combines the router prefix with the local MAC address
Stateless global unique
Provides stateful address allocation
DHCPv6
DHCPv6
DHCPv6 is the updated version of DHCP that provides dynamic IP address assignment for
IPv6 hosts. DHCPv6 is described in RFC 3315. It provides the same functions as DHCP,
with more control than stateless autoconfiguration, and it supports renumbering without
routers. DHCPv6 assignment is stateful, whereas IPv6 link-local and global unique auto-
configuration is not.
IPv6 Security
IPv6 has two integrated mechanisms to provide security for communications. It natively
supports IP Security (IPsec). IPsec is mandated at the operating-system level for all IPsec
hosts. RFC 2401 describes IPsec. Extension headers carry the IPsec AH and ESP headers.
The AH provides authentication and integrity. The ESP header provides confidentiality by
encrypting the payload. For IPv6, the AH defaults to message digest algorithm 5 (MD5),
and the ESP encryption defaults to Data Encryption Standard-cipher block chaining
(DES-CBC).
A description of the IPsec mechanisms appears in Chapter 13, “Security Solutions.” More
information also appears in RFC 2402, IP Authentication Header, and in RFC 2406, IP En-
capsulating Security Payload (ESP).
Ta ble 9 - 9 summarizes IPv6 mechanisms.
Ta b l e 9 - 9
IPv6 Mechanisms
Description
IPv6 Mechanism
Performs diagnostics and reachability information. Next header
number of 58.
ICMPv6
Discovers all nodes in the same link and checks for duplicate
addresses.
IPv6 neighbor
discovery
DNS resource record for IPv6.
AAAA
Provides stateful IPv6 address assignment.
DHCPv6
Routing protocol that uses UDP port 521.
RIPng
