•
If you configure both NetFlow and SPAN on the same interface then only the SPAN configuration is
applied and the NetFlow configuration is ignored.
•
You must configure a valid record name for every flow monitor.
•
The maximum number of supported NetFlow entries is 512,000.
•
We recommend that you configure NetFlow on a maximum of 500 destination nodes. Each interface
and module on which a particular VLAN is active is counted for the NetFlow scale. An example of a
NetFlow scale scenario is as follows
•
If ingress SVI is configured on a VLAN that is active on 3 interfaces in a single module, the
NetFlow scale is 3.
•
You cannot change the fields in a record that is applied on the monitor
•
You cannot change the sampling mode value on a sampler that is applied on the monitor
•
If NetFlow is configured on both SVI and a VLAN then only the routed packets are updated on the SVI
NetFlow.
•
NetFlow can cause high CPU loads, to prevent issues with the control plane the following limitations
apply:
•
NetFlow can be configured in the Ingress direction only
•
NetFlow packets that reach the CPU are not policed by the ASIC
•
Ingress layer 2 NetFlow is supported on the following types of interfaces:
â—¦
Layer 2 switch interface/port channel
â—¦
FEX interface
•
Ingress layer 3 NetFlow is supported on the following types of interfaces:
â—¦
Layer 3 interface/port channel
â—¦
Layer 3 sub-interface/port channel sub-interface
â—¦
SVI
•
Ingress bridged NetFlow is supported on VLANs.
How to Configure NetFlow
To configure NetFlow on a switch you perform the following steps:
•
Define a flow record by specifying key and non-key fields of interest.
•
Define one or many flow exporters by specifying export format, protocol, destination and other parameters.
•
Define a flow monitor based on the above flow record and flow exporter(s).
•
Apply the flow monitor to an interface with a sampling method specified.
   Cisco Nexus 5600 Series NX-OS System Management Configuration Guide, Release 7.x
266 OL-31641-01   
Configuring NetFlow
How to Configure NetFlow