Table of Contents
- 8.1. Troubleshooting sFlowTrend-Pro
- 8.1.1. Installation problems
- 8.1.2. No switches are listed in the Switch selector
- 8.1.3. When I select a switch in the Charts tab, the chart is blank
- 8.1.4. When I select a switch in the Interfaces tab, the table is empty
- 8.1.5. When I select a switch in the Interfaces tab, the table rows have no counter values.
- 8.1.6. sFlowTrend-Pro is not receiving sFlow from switch
- 8.1.7. sFlowTrend-Pro cannot communicate with the switch using SNMP
- 8.2. Frequently asked questions
When everything is configured correctly, Java Web
Start should automatically install sFlowTrend-Pro.
However, sometimes the browser is not aware of Java
Web Start. In this case, you have to tell it
manually to run the Java Web Start program. This is
called
javaws.
You may need to browse to the location of
javaws
- on Microsoft Windows, it should be installed in
C:\Program Files\Java\jre1.5.0_06\bin
(note the path may vary depending on the specific
version of Java installed).
When Java Web Start is installed correctly, it should
automatically be launched from the browser. If the
browser displays a text (xml) file instead, then
right-click on the link, select
save link as
or
save target as,
and save the file as
sFlowTrend.jnlp.
Then, try double-clicking on the saved file. If this
still doesn't work, then open a command prompt
window, and run
javaws sFlowTrend.jnlp
(you will need to make sure that
sFlowTrend.jnlp
is in the current directory).
sFlowTrend-Pro is written in Java, and needs a minimum of Java v5.0. Java must be installed before installing sFlowTrend-Pro. Also, in the case of other installation problems, it is often easiest just to re-install the Java JRE.
The JRE is available from Sun's java.com web site
If there are no switches listed in the Switch selector in the Charts, Interfaces, and Threshold tabs, all the charts in the Dashboard tab show Waiting for first data point and the Activity LED is not flashing then sFlowTrend-Pro is not receiving sFlow data. The Status bar should also show Configure switches/routers to monitor.
You must first configure your switches to send sFlow, see Section A.1, “Configuring switches to send sFlow”. If there are still no switches listed see Section 8.1.6, “sFlowTrend-Pro is not receiving sFlow from switch”.
If you select a switch using the Switch selector in the Charts tab and a blank screen is displayed, sFlowTrend-Pro has not received sFlow data that matches the criteria specified by the current settings in the Charts tab.
If the Interface selector is also empty, sFlowTrend-Pro is not receiving sFlow data from the switch. First ensure that the selected switch is enabled (see Section 3.1, “Selecting the switch and interface to analyse”. If the switch is enabled see Section 8.1.6, “sFlowTrend-Pro is not receiving sFlow from switch”.
-
If there are interfaces listed in the Interface selector, sFlowTrend-Pro has received sFlow data from the switch, but possibly not for the combination of the currently selected interface, chart, time, and filter. First make sure that the selected switch is enabled so that
button is showing next to the
Switch selector and that the
Status bar indicates that the switch is not
disabled.
Then change the settings in the
control bar as follows:
Charts: Top sources
Interfaces: All (this selection is only available if you are viewing a top N traffic trend chart).
Time: Last hour
Filter is disabled
For more information on settings in the Charts tab see Chapter 3, Charts.
Now wait for the Progress indicator to reach 100%.
If the Top sources chart is still not showing data, then sFlowTrend-Pro is not receiving sFlow from the switch, see Section 8.1.6, “sFlowTrend-Pro is not receiving sFlow from switch”.
If you are now seeing data in the Top sources chart, sFlowTrend-Pro is receiving sFlow data from the switch. To understand which interfaces are reporting on traffic, change to the Interfaces tab and click on the Unicasts/s column heading until the table is sorted so that rows are listed with the interface showing the highest unicasts/s listed first. If there are interfaces listed in table but there are no counter values, wait for the Progress indicator to reach 100% again (see Chapter 5, Switch interface statistics for more information on the Interfaces tab). Then click on the chart
button associated with first row. You will
now be taken to the
Charts
tab with the interface with the most
unicast/s selected.
If you select a switch using the Switch selector in the Interfaces tab and the table remains empty even after the Progress indicator has reached 100%, sFlowTrend-Pro is not receiving sFlow from that switch.
If Status bar message indicates that the switch is disabled,
enable the switch by clicking on the click the
button next to the
Switch
selector.
If the switch is enabled, then see Section 8.1.6, “sFlowTrend-Pro is not receiving sFlow from switch”.
If you select a switch using the Switch selector in the Interfaces tab and the table includes rows for the interfaces but the interface counter columns show "-" even after the Progress indicator has reached 100%, twice, sFlowTrend-Pro is receiving sFlow from the switch but the sFlow data does not include interface counters. Check that the switch is configured to export interface counters (see Section A.1, “Configuring switches to send sFlow”
If the switch has been configured using the CLI to send sFlow, follow the steps below:
Ensure that the switch is using the correct IP address and UDP port used by the host running sFlowTrend-Pro. To view and configure the IP address and UDP port used by sFlowTrend-Pro see Section 7.2.3, “Configuring advanced options”.
Ensure that there are no host or network firewalls between the switch and sFlowTrend-Pro that are blocking the sFlow packets.
There may be insufficient traffic flowing through the switch for sFlow packets to be generated using the currently configured sampling rate. Try configuring the switch to sample more frequently. See Section A.2, “Recommended sampling rates” for recommended sampling rates.
If the switch is to be configured to send sFlow by sFlowTrend-Pro using SNMP follow the steps below:
Make sure that the switch has been added to sFlowTrend-Pro, see Section 7.1.1, “Adding a switch that is to be configured using SNMP” and that the correct SNMP read/write community has been specified. Some additional configuration of the switch may be necessary to allow it to accept SNMP sets from the host running sFlowTrend-Pro, for example, see Section A.1.1.1, “Configuring ProCurve switches to allow sFlow configuration via SNMP”.
-
Use → and view the status details for the switch either by moving the mouse over the status colour indicator to activate the tooltip or by clicking on the edit
button. If the status indicates that the
switch is not sending sFlow use the
additional status message to identify the
problem:
- No SNMP
- sFlowTrend-Pro cannot communicate with the switch using SNMP. Verify that the sFlowTrend-Pro is using the correct community string and that there are no firewalls in the network or on the host that are blocking SNMP.
- Cannot configure sFlow with SNMP - SNMP write access denied
- sFlowTrend-Pro is not using the correct SNMP read/write community or the switch is not configured to allow SNMP set from the system running sFlowTrend-Pro.
- Cannot configure sFlow with SNMP - no sFlow MIB
- The switch cannot be configured via SNMP to send sFlow. Instead, you must use the switch CLI to configure sFlow (see Section A.1, “Configuring switches to send sFlow”.
- Already in use
-
Another application has
already configured this
switch to send sFlow and
there are no additional
resources to send sFlow to
sFlowTrend-Pro as well. Disable
the other application so
that the switch can be
configured by sFlowTrend-Pro.
You can identify the other
applications which have already
configured the switch by using the
edit
button. The
Additional switch details
section, under Other owners
lists the IP addresses of the other
systems which have configured the switch,
together with a description of the
application.
If the status indicates that sFlow has been successfully configured, there may be insufficient traffic flowing through the switch for sFlow packets to be generated using the currently configured sampling rate. Try changing the sFlowTrend-Pro configuration so that the switch to is configured to sample more frequently (see Section 9.3, “Custom configuration”).
If sFlowTrend-Pro cannot communicate with the switch using SNMP, it will be unable to display friendly names for the switch and its interfaces. It will also not be able to configure the switch using SNMP to send sFlow. Verify that the that the sFlowTrend-Pro is using the correct community string and that there are no firewalls in the network or on the host that are blocking SNMP.