15-3
Cisco Nexus 1000V Troubleshooting Guide, Release 5.2(1)SV3(1.1)
OL-31593-01
Chapter 15 NetFlow
Common NetFlow Problems
•
Use undefined records, exporters, samplers, or monitors.
•
Use invalid records, exporters, samplers, or monitors.
•
Modify records, exporters, samplers, or monitors after they are applied to an interface.
•
Configure a monitor on an interface that causes the VEM to run out of memory and results in a
verification error.
•
Use NetFlow in a port channel. NetFlow is not supported in port channels.
•
Configure a monitor at multiple levels of a port-profile inheritance tree.
In addition, a configuration error can occur if there is a mismatch between the UDP port configured on
the exporter and the port NetFlow Collector has listening turned on. A solution is to provide the version
number of the original command to clear the configuration and then reattempt the command.
Debugging a Policy Verification Error
You can debug a policy verification failure due to some processing on the VSM.
Step 1
Enter the
debug nfm all
command.
Step 2
Save the Telnet SSH session buffer to a file.
Step 3
Enter the
ip flow mon
monitor name direction
command.
The command executes once again and the debug traces are output to the console.
You can also use the policy verification procedure to collect logs for operations such as defining a flow
record or tracing exporter functionality.
Debugging Statistics Export
When debugging a NetFlow statistics export problem, follow these guidelines:
•
Ensure that the destination IP address is reachable from the VEMs and VSM.
•
Ensure that the UDP port configured on the exporter matches that used by the NetFlow Collector.
•
View statistics for the exporter and identify any drops by entering the
show flow exporter
command.