Basic NetFlow 2

By Chris November 30, 2015 09:05

Cisco added three small network management topics to CCNA R&S for the in 2013 (exams 100-101, 200-101, 200-120). Today’s lab gives you configuration practice with one of those: NetFlow. NetFlow provides routers with the capability to capture statistics based on watching the packets that flow into and out of router interfaces. Once captured, all the routers using NetFlow can export their data to a NetFlow collector, which is a server created to take NetFlow data, combine it, and provide more meaningful reports.

Today’s lab asks you to configure NetFlow data capture and data export with some basic requirements.


Configure a router (R2) to enable NetFlow so that it both captures and measures packet flow, as well as reporting those statistics to a NetFlow Collector. In particular:

  • Use version 9 records
  • Monitor using R1’s Gi0/1 interface
  • Monitor packets that enter that interface
  • Create loopback interface 0, with IP address and mask /32
  • Use R1’s Loopback0 interface as the source interface for reporting to the NetFlow collector
  • Use a collector port number of 2049

Figure 1: Router with IP Address


Initial Configuration

Example 1 shows the beginning configuration state of R1. Note that in this small topology, only one subnet exists at the site, with the link to the Internet. As a result, R1 happens to use a single static default route instead of an IP routing protocol. (That fact is immaterial to the NetFlow lab configuration – just didn’t want it to throw you off track.)

Example 1: R1 Config


Answer on Paper, or Maybe Test in Lab

Create your own answer, either by typing it in somewhere, or writing it on paper. Try to avoid using your notes – one of points of these labs is to move you from being able to read someone else’s config to being able to create your own from scratch.

You can easily test your NetFlow capture configuration if you create this lab on your own gear or in VIRL. However, testing NetFlow data export requires more effort and the installation of a NetFlow collector. But to test NetFlow capture, issue the show ip flow interface command. In fact, try this command before configuring NetFlow: the command should return no lines of output. Once NetFlow capture is configured, this command should list the interfaces on which NetFlow is capturing statistics.

Answers: Switch IP 1
Answers: Basic NetFlow 2
By Chris November 30, 2015 09:05
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1 Comment

  1. Bob February 20, 11:37


    Is NetFlow on the current ICND2v3 exam? I see references to NetFlow on the web and here but it is not covered in the current 200-105 study guide. I know Cisco sometimes adds topics to the exam that are not covered in their official cert guides.


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