9-12
Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter9 Completing Interface Configuration (Transparent Mode)
Completing Interface Configuration in Transparent Mode
What to Do Next
(Optional) Configure the MAC address and the MTU. See the “Configuring the MAC Address and
MTU” section on page 9-12.
(Optional) Configure IPv6 addressing. See the “Configuring IPv6 Addressing” section on
page 9-15.
Configuring the MAC Address and MTU
This section describes how to configure MAC addresses for interfaces and how to set the MTU.

Information About MAC Addresses

By default, the physical interface uses the burned-in MAC address, and all subinterfaces of a physical
interface use the same burned-in MAC address.
A redundant interface uses the MAC address of the first physical interface that you add. If you change
the order of the member interfaces in the configuration, then the MAC address changes to match the
MAC address of the interface that is now listed first. If you assign a MAC address to the redundant
interface using this command, then it is used regardless of the member interface MAC addresses.
Step3 Do one of the following:
ip address ip_address [mask] [standby
ip_address]
Example:
hostname(config-if)# ip address 10.1.1.1
255.255.255.0 standby 10.1.1.2
Sets the IP address manually.
Note For use with failover, you must set the IP address and
standby address manually; DHCP is not supported.
The ip_address and mask arguments set the interface IP address
and subnet mask.
The standby ip_address argument is used for failover. See the
“Configuring Active/Standby Failover” section on page 62-7 or
the “Configuring Active/Active Failover” section on page63-8
for more information.
ip address dhcp [setroute]
Example:
hostname(config-if)# ip address dhcp
Obtains an IP address from a DHCP server.
The setroute keyword lets the ASA use the default route supplied
by the DHCP server.
Reenter this command to reset the DHCP lease and request a new
lease.
If you do not enable the interface using the no shutdown
command before you enter the ip address dhcp command, some
DHCP requests might not be sent.
Step4 security-level number
Example:
hostname(config-if)# security-level 50
Sets the security level, where number is an integer between 0
(lowest) and 100 (highest).
Command Purpose