Configure NetFlow - Cisco Nexus

This area will help fast track you in planning, setting up and managing NetFlow in your environment. NetFlow is an embedded instrumentation within Cisco IOS Software to characterize network operation.

Network specialists of various levels within an organization need to be able to report on traffic traversing sites, key links and data centers without deploying probes. They use CySight powered by unique NetFlow Auditor methods of scalable collection, retention and Predictive AI Baslining to capture and analyze every NetFlow record with aggregation options and small footprint real-time and long-term storage. From Telco to SME you will recognize the superior reliability and performance of the CySight NetFlow Auditing solutions, as well as the management benefits offered.

Configure NetFlow - Cisco Nexus

Network Performance and Forensics for Data Center Class Switches

The Nexus 7000 is a highly scalable modular platform that delivers up to 15 terabits per second of switching capacity in a single chassis, supporting up to 512 10-gigabits-per-second (Gbps) Ethernet and future delivery of 40- and 100-Gbps Ethernet.

When dealing with very high traffic volumes, you need a flow monitoring software that is capable of handling such high rates. CySight is the only solution that has been proven to scale to suit the high rates of data centers, internet edges and corporate cores whilst still retaining the most granularity in the industry. CySight currently handles the largest NetFlow sites in the world with millions of flows per minute without melting down or losing flows.

Enabling NetFlow:
  • Nexus Switch(config)# feature netflow
Create a Flow Record:
  • As we are using the default "netflow-original" flow record there is no reason to create a new flow record
Create a Flow Exporter:
  • Nexus Switch(config)# flow exporter NetFlowAuditorExporter
    Nexus Switch(config-flow-exporter)# destination <NetFlowAuditorIPAddress>
    • e.g. destination 10.10.10.1
    Nexus Switch(config-flow-exporter)# source ethernet 1/1
    • The IP Address of ethernet 1/1 will be used and identified as the device by CySight
    Nexus Switch(config-flow-exporter)# transport udp 2055
    • Port 2055 is enabled as default but you can configure the Port to any UDP Port on CySight under "Configuration -> Devices -> UDP Port".
    Nexus Switch(config-flow-exporter)# version 9
    Nexus Switch(config-flow-exporter-version-9)# exit
    • Nexus allows v9 or v5. You can use either with CySight
Create a Flow Monitor:
  • Nexus Switch(config)# flow monitor NetFlowAuditorMonitor
    Nexus Switch(config-flow-monitor)# exporter NetFlowAuditorExporter
    Nexus Switch(config-flow-monitor)# record netflow-original
    Nexus Switch(config-flow-monitor)# exit
Setup the Flow TimeOuts:
  • Nexus Switch(config)#flow timeout active 60
    Nexus Switch(config)#flow timeout inactive 15
Enable the Flow Monitor on each Interface:
  • Nexus Switch(config)# interface ethernet 1/2
    Nexus Switch(config-if)# ip flow monitor NetFlowAuditorMonitor input [Optional Sampler Name]
    Nexus Switch(config)# interface ethernet 1/2
    Nexus Switch(config-if)# ip flow monitor NetFlowAuditorMonitor input [Optional Sampler Name]
    ...
    Nexus Switch(config)# interface ethernet 2/1
    Nexus Switch(config-if)# ip flow monitor NetFlowAuditorMonitor input [Optional Sampler Name]
    Nexus Switch(config)# interface ethernet 2/2
    Nexus Switch(config-if)# ip flow monitor NetFlowAuditorMonitor input [Optional Sampler Name]

    NOTE: Use the ip flow monitor command on every interface of the switch.

Cisco Nexus 7000 Series NX-OS System Management Configuration Guide, Release 4.0

Cisco Nexus 1000V NAM Virtual Service Blade Installation and Configuration Guide
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