Configuring Ethernet Management Ports

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Prerequisites for Ethernet Management Ports

When connecting a PC to the Ethernet management port, you must first assign an IP address.

Information about the Ethernet Management Port

The Ethernet management port, also referred to as the Fa0 or fastethernet0 port, is a Layer 3 host port to which you can connect a PC. You can use the Ethernet management port instead of the switch console port for network management. When managing a switch stack, connect the PC to the Ethernet management port on a stack member.

Ethernet Management Port Direct Connection to a Switch

Figure 1. Connecting a Switch to a PC. This figure displays how to connect the Ethernet management port to the PC for a switch or a standalone switch.

Ethernet Management Port Connection to Stack Switches using a Hub

In a stack with only stack switches, all the Ethernet management ports on the stack members are connected to a hub to which the PC is connected. The active link is from the Ethernet management port on the active switchstack masterthrough the hub, to the PC. If the activeswitch fails and a new active switch is elected, the active link is now from the Ethernet management port on the new active switch to the PC.

In a mixed stack, the stack members are connected to the PC through the Ethernet management ports. The active link is from the active switch to the PC. If the active switch fails and the elected active switch is not switch 2, the active link can be from a stack member to the PC.

Figure 2. Connecting a Switch Stack to a PC. This figure displays how a PC uses a hub to connect to a switch stack.

Ethernet Management Port and Routing

By default, the Ethernet management port is enabled. The switch cannot route packets from the Ethernet management port to a network port, and the reverse. Even though the Ethernet management port does not support routing, you may need to enable routing protocols on the port.

Figure 3. Network Example with Routing Protocols Enabled. Enable routing protocols on the Ethernet management port when the PC is multiple hops away from the switch and the packets must pass through multiple Layer 3 devices to reach the PC.

In the above figure , if the Ethernet management port and the network ports are associated with the same routing process, the routes are propagated as follows:

  • The routes from the Ethernet management port are propagated through the network ports to the network.

  • The routes from the network ports are propagated through the Ethernet management port to the network.

Because routing is not supported between the Ethernet management port and the network ports, traffic between these ports cannot be sent or received. If this happens, data packet loops occur between the ports, which disrupt the switch and network operation. To prevent the loops, configure route filters to avoid routes between the Ethernet management port and the network ports.

Supported Features on the Ethernet Management Port

The Ethernet management port supports these features:

  • Express Setup (only in switch stacks)

  • Network Assistant

  • Telnet with passwords

  • TFTP

  • Secure Shell (SSH)

  • DHCP-based autoconfiguration

  • SMNP (only the ENTITY-MIB and the IF-MIB)

  • IP ping

  • Interface features
    • Speed—10 Mb/s, 100 Mb/s, and autonegotiation

    • Duplex mode—Full, half, and autonegotiation

    • Loopback detection

  • Cisco Discovery Protocol (CDP)

  • DHCP relay agent

  • IPv4 access control lists (ACLs)

  • Routing protocols

Caution
Caution

Before enabling a feature on the Ethernet management port, make sure that the feature is supported. If you try to configure an unsupported feature on the Ethernet Management port, the feature might not work properly, and the switch might fail.


How to Configure the Ethernet Management Port

Disabling and Enabling the Ethernet Management Port

Procedure

  Command or Action Purpose
Step 1

configure terminal

Example:

Switch# configure terminal

Enters global configuration mode.

Step 2

interface fastethernet0

Example:

Switch(config)# interface fastethernet0

Specifies the Ethernet management port in the CLI.

Step 3

shutdown

Example:

Switch(config-if)# shutdown

Disables the Ethernet management port.

Step 4

no shutdown

Example:

Switch(config-if)# no shutdown

Enables the Ethernet management port.

Step 5

exit

Example:

Switch(config-if)# exit

Exits interface configuration mode.

Step 6

show interfaces fastethernet0

Example:

Switch# show interfaces fastethernet0

Displays the link status.

To find out the link status to the PC, you can monitor the LED for the Ethernet management port. The LED is green (on) when the link is active, and the LED is off when the link is down. The LED is amber when there is a POST failure.

TFTP and the Ethernet Management Port

Use TFTP to download or upload a configuration file to the boot loader.

This table describes the commands to use when downloading or uploading a configuration file to the boot loader using TFTP.

Table 1. Boot Loader Commands

Command

Description

arp [ ip_address ]

Displays the currently cached address resolution protocol (ARP) table when this command is entered without the ip_address parameter.

Enables ARP to associate a MAC address with the specified IP address when this command is entered with the ip_address parameter.

mgmt_clr

Clears the statistics for the Ethernet management port.

mgmt_init

Starts the Ethernet management port.

mgmt_show

Displays the statistics for the Ethernet management port.

ping host_ip_address

Sends ICMP ECHO_REQUEST packets to the specified network host.

boot tftp : /file-url .. .

Loads and boots an executable image from the TFTP server and enters the command-line interface.

copy tftp: / source-file-url filesystem :/ destination-file-url

Copies a Cisco IOS image from the TFTP server to the specified location.

Additional References

Related Documents

Related Topic Document Title
Bootloader configuration

Catalyst 3750-X and 3560-X Switches System Management Configuration Guide

Bootloader commands

Catalyst 3750-X and 3560-X Switches System Management Command Reference Guide

Error Message Decoder

Description Link

To help you research and resolve system error messages in this release, use the Error Message Decoder tool.

https://www.cisco.com/cgi-bin/Support/Errordecoder/index.cgi

MIBs

MIB MIBs Link

All supported MIBs for this release.

To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs

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