Cisco Nexus 1000V, Руководство по устранению неисправностей, Страница: 175 / 280

C H A P T E R
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Cisco Nexus 1000V Troubleshooting Guide, Release 5.2(1)SV3(1.1)
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NetFlow
This chapter describes how to identify and resolve problems that relate to NetFlow and includes the
following sections:
•
Information About NetFlow, page 15-1
• NetFlow Troubleshooting Commands, page 15-1
•
Common NetFlow Problems, page 15-2
Information About NetFlow
NetFlow allows you to evaluate IP traffic and understand how and where it flows. NetFlow gathers data
that can be used in accounting, network monitoring, and network planning.
A flow is a one-directional stream of packets that arrives on a source interface (or subinterface),
matching a set of criteria. You create a flow using a flow record to define the criteria for your flow. All
criteria must match for the packet to count in the given flow. Flows are stored in the NetFlow cache. Flow
information tells you the following:
•
The source address tells you who is originating the traffic.
• The destination address tells you who is receiving the traffic.
•
Ports characterize the application using the traffic.
• Class of service (CoS) examines the priority of the traffic.
•
The device interface tells how traffic is being used by the network device.
• Tallied packets and bytes show the amount of traffic.
A flow record defines the information that NetFlow gathers, such as packets in the flow and the types of
counters gathered per flow. You can define new flow records or use the predefined Cisco Nexus 1000V
flow records.
For detailed information about configuring NetFlow, see the Cisco Nexus 1000V System Management
Configuration Guide .
NetFlow Troubleshooting Commands
Use the following commands to collect information about NetFlow process runtime configuration errors.
•
show flow internal event-history errors