9-15
Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter9 Completing Interface Configuration (Transparent Mode)
Completing Interface Configuration in Transparent Mode
Configuring IPv6 Addressing
This section describes how to configure IPv6 addressing. For more information about IPv6, see the
“Information About IPv6 Support” section on page21-9 and the “IPv6 Addresses” section on page B-5.
This section includes the following topics:
•Information About IPv6, page9-15
•Configuring a Global IPv6 Address and Other Options, page9-17

Information About IPv6

This section includes information about how to configure IPv6, and includes the following topics:
•IPv6 Addressing, page 9-15
•Duplicate Address Detection, page9-15
•Modified EUI-64 Interface IDs, page9-16
•Unsupported Commands, page9-16

IPv6 Addressing

You can configure two types of unicast addresses for IPv6:
•Global—The global address is a public address that you can use on the public network. This address
needs to be configured for each bridge group, and not per-interface. You can also configure a global
IPv6 address for the management interface.
•Link-local—The link-local address is a private address that you can only use on the
directly-connected network. Routers do not forward packets using link-local addresses; they are
only for communication on a particular physical network segment. They can be used for address
configuration or for the ND functions such as address resolution and neighbor discovery. Because
the link-local address is only available on a segment, and is tied to the interface MAC address, you
need to configure the link-local address per interface.
At a minimum, you need to configure a link-local address for IPv6 to operate. If you configure a global
address, a link-local addresses is automatically configured on each interface, so you do not also need to
specifically configure a link-local address. If you do not configure a global address, then you need to
configure the link-local address, either automatically or manually.
Note If you want to only configure the link-local addresses, see the ipv6 enable (to auto-configure) or ipv6
address link-local (to manually configure) command in the command reference.

Duplicate Address Detection

During the stateless autoconfiguration process, duplicate address detection (DAD) verifies the
uniqueness of new unicast IPv6 addresses before the addresses are assigned to interfaces (the new
addresses remain in a tentative state while duplicate address detection is performed). Duplicate address
detection is performed first on the new link-local address. When the link local address is verified as
unique, then duplicate address detection is performed all the other IPv6 unicast addresses on the
interface.