Dashboard

The Dashboard is the main window for monitoring the status and performance of the switch. The Dashboard displays this information:

  Switch information

  Switch health

  Bandwidth utilization

  Packet errors received and transmitted

  Power utilization and allocation

  Port utilization

Use the Front Panel view and the Monitor menu options with the Dashboard for a more complete report of the switch status and performance.

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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:

  Bandwidth Used Gauge

  Packet Error Gauge

  Power (PoE) Gauge

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Bandwidth Used Gauge

The Bandwidth Used gauge shows the total percentage of the switch bandwidth being used. 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 bandwidth percentages that are less than 10 percent.

To completely monitor how the switch is handling network traffic, use the Bandwidth Used graph with

  Packet Error Gauge

  Trends window

  Port Statistics window

To manually refresh the gauge, click Refresh on the toolbar. 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 packets through the network. As network activity increases, contention between devices to send data through the network increases. Contention can cause collisions (two devices sending data at the same time), and the devices need to resend their data. Excessive collisions can cause transmission delays. For example, users might experience excessive delays in sending or receiving information through the network.

As you monitor the switch, note if the bandwidth utilization is consistently high, as this can mean that the network is congested. If the switch reaches its maximum bandwidth and its buffers become full, it begins to discard the data packets it receives. Some packet loss in the network is not considered unusual, and the switch is configured to help recover lost packets (such as 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. Also look for other causes, such as faulty devices or connections, that can create the high bandwidth utilization on the switch.

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Packet Error Gauge

The Packet Error gauge shows the packet error percentage for the switch. This percentage is calculated by comparing two values:

  The total number of packets that are sent and received

  The total number of error packets that are sent and received

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.

If the packet-error percentage is high, the switch bandwidth utilization might also be too high (a sign that the network is congested). To completely monitor how the switch is handling network traffic, use the Packet Error gauge with

  Bandwidth Used Gauge

  Port Utilization Graph

  Trends window

  Port Statistics window

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

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

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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 than the system buffers. Broadcast storms and bursts of noise can cause the ignored count to increase.

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Power (PoE) Gauge

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

The power gauge shows the total percentage of power that is allocated to connected devices that are receiving power from the switch. The switch automatically maintains a power budget, monitors and tracks requests for power, and grants power only when it is available. 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 power percentages that are less than 10 percent.

For a graph that shows power utilization patterns over incremental instances in time (up to ten 60-second refresh cycles), click View Trends. To manually refresh the graph, click Refresh on the toolbar.

For more information about PoE budgeting, see the switch software configuration guide.

The Support window provides a link to the switch documentation.

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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.

The device manager updates the graph at every 60-second refresh cycle. To manually refresh the graph, click Refresh on the toolbar.

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 usage, use the Port Utilization graph with

  Bandwidth Used Gauge

  Packet Error Gauge

  Trends window

  Port Statistics window

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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