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
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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.
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Product ID
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The model of this switch. This information
cannot be modified.
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IP Address
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The IP address of this switch configured
during Express Setup, through Network Assistant, or through the CLI.
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MAC Address
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The MAC address of this switch.
This information cannot be modified.
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Version ID |
The version ID of the switch. This information cannot be changed. |
Serial Number
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The serial number of this switch.
This information cannot be modified.
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Software
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The Cisco IOS software version that
this switch is running. This information is updated when you upgrade
the switch software.
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Contact
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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.
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Location
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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
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Packets that are smaller than the
allowed minimum size (less than 64 bytes).
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Giant packets
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Packets that are larger than the
allowed maximum size (more than 1518 bytes).
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Cyclic redundancy checksum
(CRC) errors
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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.
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Overrun packets
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Packets that the receiving device
was unable to receive.
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Frame packets
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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.
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Ignored packets
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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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