Brocade Communications Systems Brocate Ethernet Access Switch 6910 User Manual

Page 668

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618

Brocade 6910 Ethernet Access Switch Configuration Guide

53-1002581-01

IPv6 Interface

29

Duplicate address detection determines if a new unicast IPv6 address already exists on the
network before it is assigned to an interface.

Duplicate address detection is stopped on any interface that has been suspended (see the

vlan

command). While an interface is suspended, all unicast IPv6 addresses assigned to that

interface are placed in a “pending” state. Duplicate address detection is automatically
restarted when the interface is administratively re-activated.

An interface that is re-activated restarts duplicate address detection for all unicast IPv6
addresses on the interface. While duplicate address detection is performed on the interface’s
link-local address, the other IPv6 addresses remain in a “tentative” state. If no duplicate
link-local address is found, duplicate address detection is started for the remaining IPv6
addresses.

If a duplicate address is detected, it is set to “duplicate” state, and a warning message is sent
to the console. If a duplicate link-local address is detected, IPv6 processes are disabled on the
interface. If a duplicate global unicast address is detected, it is not used. All configuration
commands associated with a duplicate address remain configured while the address is in
“duplicate” state.

If the link-local address for an interface is changed, duplicate address detection is performed
on the new link-local address, but not for any of the IPv6 global unicast addresses already
associated with the interface.

Example

The following configures five neighbor solicitation attempts for addresses configured on VLAN 1.
The

show ipv6 interface

command indicates that the duplicate address detection process is still

on-going.

Console(config)#interface vlan 1

Console(config-if)#ipv6 nd dad attempts 5

Console(config-if)#end

Console#show ipv6 interface

VLAN 1 is up

IPv6 is enabled

Link-local address:

FE80::200:E8FF:FE90:0/64

Global unicast address(es):

2009:DB9:2229::79, subnet is 2009:DB9:2229:0::/64

Joined group address(es):

FF01::1/16

FF02::1/16

FF02::1:FF00:79/104

FF02::1:FF90:0/104

IPv6 link MTU is 1500 bytes

ND DAD is enabled, number of DAD attempts: 5.

ND retransmit interval is 1000 milliseconds

ND advertised retransmit interval is 0 milliseconds

ND reachable time is 30000 milliseconds

ND advertised reachable time is 0 milliseconds

Console#

Related Commands

ipv6 nd ns-interval (619)
show ipv6 neighbors (621)

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