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Port Utilization and Port Errors Graphs
Per-Port Utilization and Per-Port Errors Graphs
Monitoring
Read this chapter to understand the switch monitoring features that are used to evaluate the status and the performance of the switch. The tasks in this chapter are independent, unless otherwise noted, and are listed in no particular order.
Before You Begin:
The monitoring features described in this chapter are available if the switch has an IP address. Make sure that the switch has been set up as described in the Getting Started Guide for the Catalyst Express 500 Switches.
Chapter Topics:
Why Monitor the Switch
Any problem in your switch can affect a large proportion of your users. Implementing a preventive approach to switch monitoring helps you to detect problems early and to avoid potential problems.
With switch monitoring, you can gain visibility into the status and availability of switch ports. You can actively monitor switch ports and quickly notify users if a switch port or the switch fails.
When you access the device manager Dashboard and monitoring windows, you can:
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Check the overall switch status and the switch vital signs.
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Check the Front Panel LEDs
You can get a quick view of the overall condition of the switch by checking the device manager Front Panel view (Figure 4-1).
Figure 4-1 Front Panel View
The Front Panel view is a graphical display of the switch front panel. The system LEDs (Table 4-1) and port LEDs (Table 4-2) on the Front Panel view and on the physical switch match. You can use the device manager View list to change the type of information displayed by the port LEDs.
The Front Panel view shows all the switch components color-coded according to their status, and it is always visible during the device manager session. The colors help you to quickly see if a fault or an error condition exists. A Legend describes the meanings of the colors (see the "Legend of LED Colors" section).
Move the pointer over a port to display the port number, description, status, speed, duplex mode, and Power over Ethernet (PoE) status. The port speed and duplex mode for a port only appear in the pop-up window when a device is connected to the port. The PoE status is available only if the port is a PoE port.
The Uptime field shows how long the switch has been operating since it was last powered on or was restarted. Status is automatically refreshed every 60 seconds or when you click Refresh on the toolbar. The refresh counter shows the number of seconds left before the next refresh cycle starts.
System LEDs
For the meanings of the system LED colors, see Table 4-4.
Table 4-1 System LEDs
The status of the switch (system).
The presence of a switch problem.
When the switch detects a problem on one or more ports, the Alert LED turns amber. Move the pointer over the Alert LED to display a description of the most recent problem detected, the port on which the problem exists, and the time that it was detected. The Alert LED stays amber until the Alert Log is cleared. The link to the Alert Log provides more details about the problem. For more information about the Alert Log, see the "Check the Alert Log" section.
The status of PoE being provided to the ports.
The status of the redundant power supply (RPS) if one is connected to the switch.
The configuration mode in which the switch is operating.
The SETUP button on the Front Panel view is not active.
Port LEDs
Choose an LED mode from the View list to change the type of information displayed through the port LEDs. Note that changing the modes of the LEDs is available only through the device manager.
For the meanings of the port LED colors, see Table 4-3.
Legend of LED Colors
From the device manager, you can use the Legend (Figure 4-2, Table 4-3, and Table 4-4) to display a color-coded explanation of the icons and colors used on the device manager windows.
To display the Legend, click Legend from the device manager tool bar. You can also click Legend from the device manager online help menu.
Figure 4-2 LED Legend
Check the Status Field
The Status field (Figure 4-3) displays the severity and number of problems (hardware issues and misconfigurations) on the switch. If no problems exist, the field shows that the overall switch operation is normal. This field is always visible during the device manager session. It is below the Front Panel view.
Figure 4-3 Status Field
Choose a problem in the list, and then click Get Details. This displays a complete troubleshooting report, including the problem highlighted and recommended actions to resolve the problem. For information about diagnostics, see the "Run a Diagnostic Test" section on page 5-2.
View the Alert Log for the details of the problems and the most recent time at which the switch detected the problems. For information about the log, see the "Check the Alert Log" section.
Check the Dashboard
The Dashboard (Figure 4-4) is the main window for monitoring the switch status and performance. It is the default window and appears each time you display the device manager. To display the Dashboard, choose Dashboard from the device manager menu.
Figure 4-4 Switch Dashboard
The Dashboard displays:
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Switch Information
The Switch Information area on the Dashboard displays this information about the switch:
Bandwidth Used Gauge
The Bandwidth Used gauge shows the total percentage of the switch bandwidth being used. 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. For a graph that shows bandwidth utilization patterns over incremental instances in time (by 60 seconds, 60 minutes, 24 hours, or 14 days), see the "Bandwidth Utilization Graph" section.
The Bandwidth Used gauge changes as the switch experiences the network activity from devices sending data through the network. As network activity increases, so does contention between devices to send data through the network. As you monitor utilization on the switch, note whether the percentage of usage is what you expect during that given time of network activity. If utilization is high when you expect it to be low, perhaps a problem exists.
As you monitor the switch, note if the bandwidth utilization is consistently high. This can mean there is congestion in the network. If the switch reaches its maximum bandwidth (above 90 percent utilization) 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 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 utilization on the switch.
Packet Error Gauge
The Packet Error gauge shows the total packet error percentage for the switch. 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 packet errors under 5 percent.
Data is collected at each 60-second system refresh. To see a graph that shows packet error percentages over incremental instances in time (by 60 seconds, 60 minutes, 24 hours, or 14 days), see the "Packet Error Graph" section.
The packet error percentage is calculated by comparing two values:
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If the packet-error percentage is high (that is, above 10 percent), the switch bandwidth utilization 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 (Table 4-5) collected by the switch. The type of packet error can help you to identify a more precise cause for some network problems. For more information about port statistics, see the "Check the Port Statistics" section.
These are some types of packet errors.
PoE Gauge
The PoE Utilization gauge is only for switches with 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 utilization under 5 percent.
Data is collected at each 60-second system refresh. For a graph that shows power utilization patterns over incremental instances in time (up to ten 60-second refresh cycles), see the "PoE Utilization Graph" section.
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.
Fan Status
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. A malfunctioning fan can affect the internal temperature of the switch. Check the thermometer graphic to see if the switch has reached an unacceptably high temperature.
Temperature Status
Use the thermometer with the animated fan to monitor the switch internal temperature environment. The thermometer graphic displays:
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Switch internal temperature is within the acceptable temperature range.
Red
Switch internal temperature is above the upper temperature threshold.
For information about the switch temperature range and the operating environment guidelines, see the "Installation Guidelines" section and the "Technical Specifications" section on page A-1.
Port Utilization and Port Errors Graphs
At a glance, you can see the following information on port performance:
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Bandwidth allocation can also be based on whether the connection is operating in half-duplex or full-duplex mode.
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These are some of the reasons for errors received on and sent from the switch ports:
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Data is collected at each 60-second system refresh. For a graph that shows per-port patterns over incremental instances in time (by 60 seconds, 60 minutes, 24 hours, or 14 days), see the "Per-Port Utilization and Per-Port Errors Graphs" section. For details on the specific port errors detected on each port, see the "Check the Port Statistics" section.
Check the Trends Graphs
Use the Trends window (Figure 4-5) to display the historical trends graphs. Use these graphs to display the switch bandwidth, the port usage, and the percentage of packet errors detected by the switch. You can display the data in increments of seconds, minutes, hours, and days. The granularity of these graphs can help you to analyze traffic patterns and to identify problems with the switch and individual ports.
Tip
To display the Trends window, choose Monitor > Trends. You also can click the View Trends link from Dashboard.
The Trends window displays these graphs:
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Figure 4-5 Trends Window
Bandwidth Utilization Graph
The Bandwidth Utilization graph shows the same information as the Bandwidth Used gauge on the Dashboard, except that the graph can show bandwidth usage patterns over incremental instances in time (by 60 seconds, 60 minutes, 24 hours, or 14 days). This graph also marks the highest peak reached. The default is 60 seconds.
If you see sharp increases in switch usage, use this graph to determine when unusual peaks in network usage occur. For more information about bandwidth usage, see the "Bandwidth Used Gauge" section.
Packet Error Graph
The Packet Error graph shows the same information as the Packet Error gauge on the Dashboard, except that the graph can show the percentage of packet errors collected over incremental instances in time (by 60 seconds, 60 minutes, 24 hours, or 14 days). The default is 60 seconds.
Use this graph to audit the effects that connected devices have on the switch performance or the network. For example, if you suspect that a connected device is sending error packets, you can check if the data on the graph changes when you disconnect and reconnect the suspected device. For more information about packet errors, see the "Packet Error Gauge" section.
PoE Utilization Graph
The PoE Utilization graph is only available if the switch is a PoE switch. This graph shows the same information as the PoE Utilization gauge on the Dashboard. The percentage of power allocated is shown over ten 60-second system refresh cycles. For more information about power allocation, see the "PoE Gauge" section.
Per-Port Utilization and Per-Port Errors Graphs
The Port Utilization and Port Errors graphs on the Trends window show the same information as the Port Utilization and Port Errors graphs on the Dashboard, except that the graphs on the Trends window can show the usage patterns of a specific port over incremental instances in time (by 60 seconds, 60 minutes, 24 hours, or 14 days). The default is 60 seconds.
To display the trends for a specific port, choose a port from the Port list.
Use these graphs to observe the performance of a specific port. For example, if a network user is having intermittent network connectivity, use the Port Utilization graph to observe the traffic patterns on the port to which the user's PC is connected, and use the Port Errors graph to see if the port is receiving or sending error packets.
For more information about port usage and port errors, see the "Port Utilization and Port Errors Graphs" section.
Check the Port Status
If the switch has link issues, such as traffic not being received on a switch port, use the Port Status window (Figure 4-6) to check the basic port status, to make sure that the speed and duplex mode of the switch port and the connected device match, and to check that the port is in the correct VLAN.
If the switch has link issues, such as traffic is not being received on a switch port, use this window to verify that the port settings are correct. You can check switch ports before connecting devices to the port to confirm that the settings of both devices match.
Figure 4-6 Port Status Window
The Port Status window displays this information
Check the Port Statistics
Use the Port Statistics window to display the statistics for data sent from and received by the switch ports since the switch was last powered on, was restarted, or since the statistics were last cleared.
The types of port statistics collected and displayed are grouped under these tabs on the Port Statistics window:
To display the Port Statistics window, choose Monitor > Port Statistics from the device manager menu. You also can click the View Port Statistics link from Dashboard.
To clear the data from the statistics tables, click Clear Counters from the window.
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See the device manager online help for additional guidelines and procedures.
Figure 4-7 Port Statistics Window
Overview Tab
The Overview tab displays:
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This tab displays the specific numbers of error packets received on and sent from the port, which is a granularity that is not available from the Dashboard and Trends graphs. The number of error packets can mean a duplex mismatch, incompatibilities with the port and its attached device, or faulty cables or attached devices. Any of these problems can cause slow network performance, data loss, or lack of connectivity. For example, to troubleshoot problems regarding loss of connectivity, clear the statistics for the port in question, and see if the port continues to receive and send packets.
Transmit Detail Tab
The Transmit Detail tab displays:
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You can use the statistics on this tab to troubleshoot unusual changes in network traffic. If a port is sending an unusually high amount of traffic (such as multicast or broadcast packets), check the connected device to see if this traffic pattern is normal or could mean a problem.
Receive Detail Tab
The Receive Detail tab displays:
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You can use the statistics on this tab to troubleshoot unusual changes in network traffic. If a port is receiving an unusually high amount of traffic (such as multicast or broadcast packets), check the connected device to see if this traffic pattern is normal for the connected device or could mean a problem.
Check the Alert Log
The Alert Log displays switch problems that happened since the log was last cleared. The problems are issues that should be or have already been solved.
To display the Alert Log, choose Monitor > Alert Log from the device manager menu. You can also click the Alert Log link in the popup when you move your pointer over the amber Alert LED.
Tip
The Alert LED stays amber until the Alert Log is cleared. Click the Clear Log button to acknowledge that you have read the alerts and to turn off the amber Alert LED.
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See the device manager online help for the guidelines and procedures on how to use the Alert Log.
The Alert Log includes this information (see also Figure 4-8):
Figure 4-8 Sample Alert Log
When You Are Done
If needed, see Chapter 3, "Customization" to change or to verify feature settings, or see Chapter 5, "Troubleshooting" to identify and resolve problems.
