Cisco ASA 5505 Configuration Manual page 255

Chapter 8 Configuring Interfaces
To manually assign a MAC address to this interface, enter a MAC address in the Active Mac Address
Step 5
field in H.H.H format, where H is a 16-bit hexadecimal digit.
For example, the MAC address 00-0C-F1-42-4C-DE would be entered as 000C.F142.4CDE. The first
two bytes of a manual MAC address cannot be A2 if you also want to use auto-generated MAC addresses.
Step 6 If you use failover, enter the standby MAC address in the Standby Mac Address field. If the active unit
fails over and the standby unit becomes active, the new active unit starts using the active MAC addresses
to minimize network disruption, while the old active unit uses the standby address.
What to Do Next
(Optional) Configure IPv6 addressing. See the
Configuring IPv6 Addressing
This section describes how to configure IPv6 addressing. For more information about IPv6, see the
"Information About IPv6 Support" section on page 18-8
For transparent mode, use this section for the Management 0/0 or 0/1 interface. To configure the global
IPv6 management address for transparent mode, see the
page
transparent mode according to the
Firewall Mode)" section on page
Information About IPv6 Addressing
When you configure an IPv6 address on an interface, you can assign one or several IPv6 addresses to the
interface at one time, such as an IPv6 link-local address and a global address. However, at a minimum,
you must configure a link-local address.
Every IPv6-enabled interface must include at least one link-local address. When you configure a global
address, a link-local addresses is automatically configured on the interface, so you do not also need to
specifically configure a link-local address. These link-local addresses can only be used to communicate
with other hosts on the same physical link.
When IPv6 is used over Ethernet networks, the Ethernet MAC address can be used to generate the 64-bit
interface ID for the host. This is called the EUI-64 address. Because MAC addresses use 48 bits,
additional bits must be inserted to fill the 64 bits required. The last 64 bits are used for the interface ID.
For example, FE80::/10 is a link-local unicast IPv6 address type in hexadecimal format.
Information About 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.
Duplicate address detection is suspended on interfaces that are administratively down. While an
interface is administratively down, the unicast IPv6 addresses assigned to the interface are set to a
pending state. An interface returning to an administratively up state restarts duplicate address detection
for all of the unicast IPv6 addresses on the interface.
OL-20339-01
9-16. If you do not configure a management address, you can configure the link-local addresses in
"Configuring IPv6 Addressing" section on page
and the
"Configuring the IPv6 Address" section on
"Configuring the Link-Local Address on an Interface (Transparent
8-30.
Cisco ASA 5500 Series Configuration Guide using ASDM
Completing Interface Configuration (All Models)
"IPv6 Addresses" section on page
8-27.
A-5.
8-27