Configuring a Fast Ethernet Interface

To configure properties on a Fast Ethernet interface:

  1. From the configuration page, as shown in Figure 1, select the Fast Ethernet interface you want to configure.

    The properties you can configure on a Fast Ethernet interface are displayed, as shown in Figure 4.

    Figure 4: Fast Ethernet Interfaces Configuration Page

    Fast Ethernet Interfaces Configuration
  2. Enter information into the Configure Interfaces page, as described in Table 7.
  3. Click one of the following buttons:
    • To apply the configuration and return to the configuration page that lists all the interfaces, click OK.
    • To cancel your entries and return to the Configure Interfaces page, click Cancel.

Table 7: Fast Ethernet Configuration Summary



Your Action

Logical Interfaces

Add logical interfaces

Defines one or more logical units that you connect to this physical Fast Ethernet interface. You must define at least one logical unit for a Fast Ethernet interface. You can define multiple units if the encapsulation type is Frame Relay.

Click Add.

Logical Interface Description

(Optional) Describes the logical interface.

Type a text description of the logical interface to more clearly identify it in monitoring displays.

IPv4 Addresses and Prefixes

Specifies one or more IPv4 addresses for the interface.

  1. Click Add.
  2. Type one or more IPv4 addresses and prefixes. For example:

  3. Click OK.

ARP Address

Enables the device to create a static Address Resolution Protocol (ARP) entry for this interface by specifying the IP address of a node to associate with its media access control (MAC) address. The IP address must be in the same subnet as the IPv4 address or prefix of the interface you are configuring.

Static ARP entries associate the IP addresses and MAC addresses of nodes on the same subnet, enabling a device to respond to ARP requests having destination addresses that are not local to the incoming interface.

Type an IPv4 address that you want to associate with the MAC address; for example,

MAC Address

Specifies the hardware media access control (MAC) address associated with the ARP address.

The MAC address uniquely identifies the system and is expressed in the following format: mm:mm:mm:ss:ss:ss. The first three octets denote the hardware manufacturer ID, and the last three are serial numbers identifying the device.

Type the MAC address to be mapped to the ARP entry; for example, 00:12:1E:A9:8A:80.


Enables the device to reply to ARP requests for the specified address.

  • To enable publishing, select the check box.
  • To disable publishing, clear the check box.

Physical Interface Description

(Optional) Adds supplementary information about the physical Fast Ethernet interface.

Type a text description of the Fast Ethernet interface to more clearly identify it in monitoring displays.

MTU (bytes)

Specifies the maximum transmission unit (MTU) size for the Fast Ethernet interface.

Type a value between 256 bytes and one of the following values:

  • For built-in Fast Ethernet interfaces and Dual-Port Fast Ethernet PIM interfaces, 9192 bytes
  • For 4-port Fast Ethernet ePIM interfaces, 1514 bytes

The default MTU for Fast Ethernet interfaces is 1514.

Redundant Parent

Specifies the name of the redundant Ethernet interface that a physical interface is associated with to form a redundant Ethernet interface pair.

Specify a redundant Ethernet interface name.

You can also manually set the speed and link mode for a Fast Ethernet interface using the CLI commands set interfaces fe-pim/0/port speed 10m | 100m and set interfaces fe-pim/0/port link-mode half-duplex | full-duplex.