Dashboard

The Dashboard provides information about the switch and is the main window for monitoring the switch status and its performance. It is the default window and appears each time that you display the device manager. The Dashboard displays:

Tips on using this window:

  • Click Refresh to update the information displayed. The information on this window is automatically updated at each system refresh (every 60 seconds).
  • The Front Panel view LEDs also provide information for monitoring the switch and its ports.

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Switch Information

The Switch Information area provides reference information about the switch.

Name

The name of this switch configured during Express Setup, through Network Assistant, or through the command-line interface (CLI). If no name was provided, this field displays the default name, Switch.

Product ID

The model of this switch. This information cannot be modified.

IP Address

The IP address of this switch configured during Express Setup, through Network Assistant, or through the CLI.

MAC Address

The MAC address of this switch. This information cannot be modified.

Version ID The version ID of the switch. This information cannot be changed.

Serial Number

The serial number of this switch. This information cannot be modified.

Software

The Cisco IOS software version that this switch is running. This information is updated when you upgrade the switch software.

Contact

The name of the person assigned as the administrative contact for this switch. This information is configured during Express Setup, through Network Assistant, or through the CLI.

Location

The location identified for this switch. This information is configured during Express Setup, through Network Assistant, or through the CLI.

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Switch Health

The Switch Health area has gauges and indicators that show the overall status of the switch, such as:

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Bandwidth Used Gauge

The Bandwidth Used gauge shows the total percentage of the switch bandwidth being used. You can also move the pointer over the gauge to see this percentage. Each bar in the gauge represents 10 percent and does not show increments that are less than 10 percent. The gauge does not show total bandwidth under 5 percent.

Data is collected at each 60-second system refresh. To manually refresh the gauge, click Refresh. For a graph that shows bandwidth utilization patterns over incremental instances in time (up to ten 60-second refresh cycles), click View Trends.

The Bandwidth Used gauge changes as the switch experiences the network activity from devices sending data through the network. As network activity increases, contention between devices to send data through the network increases. As you monitor usage on the switch, note whether the percentage of usage is what you expect during that given time of network activity. If usage is high when you expect it to be low, perhaps a problem exists.

As you monitor the switch, note whether the bandwidth usage is consistently high. This can mean there is congestion in the network. If the switch reaches its maximum bandwidth (above 90 percent usage) and its buffers become full, it begins to discard the data packets that it receives. Some packet loss in the network is not considered unusual, and the switch is configured to help to recover lost packets (such as by signaling to other devices to resend data). However, excessive packet loss can create packet errors, which can degrade overall network performance.

To reduce congestion, consider segmenting the network into subnetworks that are connected by other switches or routers. Look for other causes, such as faulty devices or connections, that can also increase bandwidth usage on the switch.

To thoroughly monitor how the switch is handling network traffic, see

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Packet Error Gauge

The actual percentage appears below the graphic. You can also display the actual percentage by moving the pointer over the gauge. Each bar in the gauge represents 10 percent, and does not show increments that are less than 10 percent. The gauge does not show packet error percentages that are less than 10 percent.

Data is collected at each 60-second system refresh. To manually refresh the gauge, click Refresh. To see a graph that shows packet error percentages over incremental instances in time (up to ten 60-second refresh cycles), click View Trends.

The packet error percentage is calculated by comparing two values:

  • The total number of packets that are sent and received
  • The total number of packets with errors that are sent and received

If the packet-error percentage is high (that is, above 10 percent), the switch bandwidth usage might also be too high (a sign that the network is congested). Other causes for packet errors are faulty cabling and port misconfigurations, such as a duplex-mode mismatch. These problems can cause network users to experience intermittent connectivity or loss of connectivity to network resources (such as servers and printers) or to the Internet. Excessive collisions can cause transmission delays. For example, users might experience excessive delays in sending or receiving information through the network.

The Port Statistics window displays some of the types of packet errors collected by the switch. The type of packet error can help you to identify a more precise cause for some network problems.

To thoroughly monitor how the switch is handling network traffic, see

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Types of Packet Errors

These are some types of packet errors.

Runt packets

Packets that are smaller than the allowed minimum size (less than 64 bytes).

Giant packets

Packets that are larger than the allowed maximum size (more than 1518 bytes).

Cyclic redundancy checksum (CRC) errors

Errors generated by the originating LAN station or far-end device do not match the checksum calculated from the data received. On a LAN, this usually means noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or of a station sending bad data.

Overrun packets

Packets that the receiving device was unable to receive.

Frame packets

Packets received because of a CRC error and a noninteger number of octets. On a LAN, this is usually the result of collisions or a malfunctioning Ethernet device.

Ignored packets

Packets that the interface ignores because the interface hardware is low on internal buffers. These buffers are different from the system buffers. Broadcast storms and bursts of noise can cause the ignored count to increase.

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PoE Gauge

The PoE Utilization gauge is only for switches with Power over Ethernet (PoE) ports.

The power gauge shows the total percentage of power that is allocated to connected devices that are receiving power from the switch. Move the pointer over the gauge to display the actual percentage of power (in watts) that is used and is remaining. Each bar in the gauge represents 10 percent and does not show increments that are less than 10 percent. The gauge does not show total PoE usage under 5 percent.

Data is collected at each 60-second system refresh. To manually refresh the graph, click Refresh.

The switch automatically maintains a power budget, monitors and tracks requests for power, and grants power only when it is available. If the switch is powering attached PoE devices, you should expect to see activity on this gauge.

For more information about PoE budgeting, see Network Assistant or the CLI.

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Port Utilization Graph

The Port Utilization graph displays the receive utilization (blue) and transmit utilization (purple) for all the ports. Move the pointer over the color-coded bars in the graph for the utilization percentage for the specific ports.

Data is collected at each 60-second system refresh. To manually refresh the graph, click Refresh.

Note: Using the Refresh option from your browser reloads the device manager.

For a graph that shows per-port utilization patterns over incremental instances in time (up to ten 60-second refresh cycles), click View Trends. For send and receive statistics for each port, click View Port Statistics.

To have a better understanding on port performance, see:

The proportion of bandwidth allocated to each port can be based on symmetric (evenly distributed bandwidth to each port) or asymmetric (unlike, or unequal, bandwidth among some ports) connections.

 • Symmetric connections are among ports with the same bandwidth, such as all 100BASE-T. Symmetric connections are optimized for a reasonably distributed traffic load, such as in a peer-to-peer desktop environment.

 • Asymmetric connections are among ports with unlike bandwidth, such as a combination of 10BASE-T, 100BASE-T, and 1000BASE-T. Asymmetric connections are optimized for client/server traffic flows in which multiple clients simultaneously communicate with a server, requiring more bandwidth dedicated to the server port to prevent a bottleneck at that port.

Bandwidth allocation can also be based on whether the connection is operating in half-duplex or full-duplex mode.

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