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IPv6 Routing
Internet Protocol Version 6 (IPv6) is the successor to IPv4. Due to the rapid growth in internet users and IP addresses, IPv4 is
reaching its maximum usage.
IPv6 will eventually replace IPv4 usage to allow for the constant expansion.
This chapter provides a brief description of the differences between IPv4 and IPv6, and the Dell Networking support of IPv6.
This chapter is not intended to be a comprehensive description of IPv6.
Topics:
Protocol Overview
Implementing IPv6 with Dell Networking OS
Configuration Tasks for IPv6
Configuring IPv6 RA Guard
Protocol Overview
IPv6 is an evolution of IPv4. IPv6 is generally installed as an upgrade in devices and operating systems. Most new devices and
operating systems support both IPv4 and IPv6.
Some key changes in IPv6 are:
Extended address space
Stateless autoconfiguration
Header format simplification
Improved support for options and extensions
Extended Address Space
The address format is extended from 32 bits to 128 bits. This not only provides room for all anticipated needs, it allows for the
use of a hierarchical address space structure to optimize global addressing.
Stateless Autoconfiguration
When a booting device comes up in IPv6 and asks for its network prefix, the device can get the prefix (or prefixes) from an
IPv6 router on its link. It can then autoconfigure one or more global IPv6 addresses by using either the MAC address or a private
random number to build its unique IPv6 address.
Stateless autoconfiguration uses three mechanisms for IPv6 address configuration:
Prefix Advertisement Routers use Router Advertisement messages to announce the network prefix. Hosts then use
their interface-identifier MAC address to generate their own valid IPv6 address.
Duplicate Address Detection (DAD) Before configuring its IPv6 address, an IPv6 host node device checks whether
that address is used anywhere on the network using this mechanism.
Prefix Renumbering Useful in transparent renumbering of hosts in the network when an organization changes its
service provider.
NOTE:
As an alternative to stateless autoconfiguration, network hosts can obtain their IPv6 addresses using the dynamic
host control protocol (DHCP) servers via stateful auto-configuration.
NOTE: Dell Networking OS provides the flexibility to add prefixes on Router Advertisements (RA) to advertise responses
to Router Solicitations (RS). By default, RA response messages are sent when an RS message is received. Enable the RA
response messages with the ipv6 nd prefix default command in INTERFACE mode.
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