Procedure

Step 1

In the left pane, click Security Devices.

Step 2

Click the Devices tab to locate the device or the Templates tab to locate the model device.

Step 3

Click the FTD tab and click the device whose interfaces you want to configure.

Step 4

Click Interfaces in the Management pane at the right.

Step 5

On the Interfaces page, select the physical interface you want to configure and in the Actions pane at the right, click + New Subinterface.

Notice that the Parent Interface field shows the name of the physical interface for which you are creating this subinterface. You cannot change the parent interface after you create the subinterface.

Step 6

Give the subinterface a logical name and, optionally, a description. Without a logical name, the rest of the interface configuration is ignored.

Note

If you change the name, the change is automatically reflected everywhere you used the old name, including security zones, syslog server objects, and DHCP server definitions. However, you cannot remove the name until you first remove all configurations that use the name, because you typically cannot use an unnamed interface for any policy or setting.

Step 7

Configure the VLAN ID and Subinterface ID:

VLAN ID - Enter a VLAN ID between 1 and 4094 that will be used to tag the packets on this subinterface.
Subinterface ID - Enter the subinterface ID as an integer between 1 and 4294967295. The number of subinterfaces allowed depends on your platform. You cannot change the subinterace ID after you create the subinterface.

Continue with Configure IPv4 Addressing for the Subinterface and Configure IPv6 Addressing for the Subinterface.