The Dashboard is the main window for monitoring the status and
performance of the switch. The Dashboard displays this information
Use these other monitoring-related features with the Dashboard
for a more complete report of the switch status and performance:
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. |
Type
|
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. |
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. |
The Switch Health area has gauges and indicators that show the
overall status of the switch, such as:
The Bandwidth Used gauge shows the total percentage of the switch
bandwidth being used. To completely monitor how the switch is handling
network traffic, use the Bandwidth Used graph with
- Packet Error gauge on the Dashboard
- 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 indicate that the switch 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 retransmit 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 check for
other factors, such as faulty devices or connections, that can cause
the high bandwidth utilization on the switch.
The Packet Error gauge shows the switch total packet error percentage.
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
If the packet-error percentage is high, the switch bandwidth utilization
might also be too high (a sign that the switch is congested). To
completely monitor how the switch is handling network traffic, use
the Packet Error gauge with
- Bandwidth Used gauge on the Dashboard
- Port Utilization graph on the Dashboard
- 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.
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 transmitting
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. |
This indicator is only on switches with a fan (or blower).
The animated fan shows whether the fan (or blower) on the switch
is rotating and thus is functioning normally. If the fan is not
rotating, check the physical switch. Also refer to the switch hardware
installation guide for information about the correct operating temperature
range for the switch and for troubleshooting information.
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 transmit 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 on the Dashboard
- Packet Error gauge on the Dashboard
- 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 between some ports) connections.
- Symmetric connections are between 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 between 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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