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Netflow Configuration on IOS 15


First of all, this board has been instramental in helping us through a number of issues we have had in building out our new corporate headquarters.  I do have a netflow question that has got me this time.  Below is my netflow config on a set of 4, 3750's stackwise running IOS 15.  I am not getting an packet leaving the switches nor am I seeing any on my cacti server.  I have checked the server and not blocking on the iptables firewall.  Below in my config:

flow record TWI-2E-SW1
match ipv4 destination address
collect counter flows
flow exporter Cacti
description Cacti Server
transport udp 2055
export-protocol netflow-v5
flow monitor Cacti
description Cacti Netflow Tool
record TWI-2E-SW1
exporter Cacti


ip flow-export version 5

ip flow-export destination 2055

ip flow-export destination 2055


interface GigabitEthernet1/1/4
description Primary East connection to TWI-DC-E1 port 7/2
switchport trunk encapsulation dot1q
switchport mode trunk
ip flow ingress
ip flow egress
ip flow monitor Cacti layer2-switched input
ip flow monitor Cacti layer2-switched output

interface GigabitEthernet4/1/4

description Secondary East connection to TWI-DC-W1 port 7/22
switchport trunk encapsulation dot1q
switchport mode trunk
ip flow ingress
ip flow egress


Show IP flow export


TWI-2E-SW1#sh ip flow export

Flow export v5 is enabled for main cache

  Export source and destination details :

  VRF ID : Default

    Destination(1) (2055)

    Destination(2) (2055)

  Version 5 flow records

  0 flows exported in 0 udp datagrams

  0 flows failed due to lack of export packet

  0 export packets were sent up to process level


Thanks again

Marvin Rhoads
VIP Community Legend

The 3750 only supports NetFlow with the optional services module. Can you confirm your hardware modules and revision?



Configuration guide:


We are using the following:

C3KX-NM-1G=  1 GB Network Module


I am looking for the revision number as well. 


Revision info:

General SFP Information


Identifier            :   0x03

Connector             :   0x07

Transceiver           :   0x00 0x00 0x00 0x01 0x00 0x00 0x00 0x00

Encoding              :   0x01

BR_Nominal            :   0x0D

Vendor Name           :   CISCO-FINISAR

Vendor Part Number    :   FTLF8519P2BCL-C5

Vendor Revision       :   0x41 0x20 0x20 0x20

Vendor Serial Number  :   FNS16330EY4


I suspected as much since your configuration cites "interface GigabitEthernet1/1/4" (and 4/1/4) vs. TenGigabitEthernet x/1/x.

Only with the:


Service Module with two 10GbE SFP+ ports network module for Netflow and MACsec encryption you get NetFlow to work on the 3750X.

Crud, I was worried about that when I saw your whitepaper.  If I can sneak another question in, Same subject but 6500.

I have a SUP-2T-10G and want to apply on gig module blabe (WS-6724-SFP).  Am I goign to have problems.  I continue to research this to see if supported.  also, I have a vlan directly connected to my firewalls.  Can I add to vlan at minimum.

thansk as always.

You're welcome.

You should be able to setup a Netflow export on a 6509 with SUP-2T-10G. See this helpful reference:

You could also use your firewall, assuming it's a Cisco ASA.

Please rate helpful replies.

Here is my problem.  I believe all those are for IOS 12.  I am running Version 15.0(1)SY1 on my 6500s, and having a devil of a time finding documents on this code.  I am pretty confident the commands have changed. Any docs you found that can help me.


The source documentation for configuring Flexible NetFlow on IOS 15.0SY can be found here: