Brocade TurboIron 24X Series Configuration Guide - Manual (Page 170)

136 Brocade TurboIron 24X Series Configuration Guide
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IPv6 CLI command support
IPv6 stateless autoconfiguration
TurboIron X Series devices use the IPv6 stateless autoconfiguration feature to enable a host on a
local link to automatically configure its interfaces with new and globally unique IPv6 addresses
associated with its location. The automatic configuration of a host interface is performed without
the use of a server, such as a Dynamic Host Configuration Protocol (DHCP) server, or manual
configuration.
The automatic configuration of a host interface works in the following way: a switch on a local link
periodically sends switch advertisement messages containing network-type information, such as
the 64-bit prefix of the local link and the default route, to all nodes on the link. When a host on the
link receives the message, it takes the local link prefix from the message and appends a 64-bit
interface ID, thereby automatically configuring its interface. (The 64-bit interface ID is derived from
the MAC address of the host NIC.) The 128-bit IPv6 address is then subjected to duplicate address
detection to ensure that the address is unique on the link.
The duplicate address detection feature verifies that a unicast IPv6 address is unique before it is
assigned to a host interface by the stateless auto configuration feature. Duplicate address
detection uses neighbor solicitation messages to verify that a unicast IPv6 address is unique.
NOTE
For the stateless auto configuration feature to work properly, the advertised prefix length in switch
advertisement messages must always be 64 bits.
The IPv6 stateless autoconfiguration feature can also automatically reconfigure a host interfaces if
you change the ISP for the host network. (The host interfaces must be renumbered with the IPv6
prefix of the new ISP.)
The renumbering occurs in the following way: a switch on a local link periodically sends
advertisements updated with the prefix of the new ISP to all nodes on the link. (The advertisements
still contain the prefix of the old ISP.) A host can use the addresses created from the new prefix and
the existing addresses created from the old prefix on the link. When you are ready for the host to
use the new addresses only, you can configure the lifetime parameters appropriately using the ipv6
nd prefix-advertisement command. During this transition, the old prefix is removed from the switch
advertisements. At this point, only addresses that contain the new prefix are used on the link.
IPv6 CLI command support
Table 30 lists the IPv6 CLI commands supported.
TABLE 30 IPv6 CLI command support
IPv6 command Description Switch code Router code
clear ipv6 cache Deletes all entries in the dynamic host cache. X
clear ipv6 neighbor Deletes all dynamic entries in the IPv6 neighbor
table. X X
copy tftp Downloads a copy of a software image from a
TFTP server into the system flash using IPv6. X X
ipv6 debug Enables IPv6 debugging. X X
ipv6 dns domain-name Configures an IPv6 domain name. X X
ipv6 dns server-address Configures an IPv6 DNS server address. X X