Cisco 3750-X NetFlow Support

Posted in NetFlow, Network Traffic Analysis on August 10th, 2011 by Joanne
Cisco 3750-X NetFlow Support

Cisco’s Catalyst 3750-X now has NetFlow v9 support!!

Using the 3KX module pictured below, you can now configure Flexible NetFlow exports on the 3750-X.  To find out how, just read on…..


3KX Service Module

Flexible NetFlow Support

This new module supports NetFlow v9 and Flexible NetFlow.  NetFlow is implemented in hardware so there’s no impact at all on CPU.  Here’s an example of a flow record for the 3KX Network Module.

flow record NetFlow
match datalink mac source-address
match datalink mac destination-address
match ipv4 tos
match ipv4 ttl
match ipv4 protocol
match ipv4 source address
match ipv4 destination address
match transport source-port
match transport destination-port
collect interface input snmp
collect interface output snmp
collect counter bytes
collect counter packets
collect timestamp sys-uptime first
collect timestamp sys-uptime last

You’ll also want to enable both ingress and egress on the 10G uplink ports as they are the only interfaces on the 3KX that support NetFlow export.

interface TenGigabitEthernet1/1/1
switchport trunk encapsulation dot1q
switchport mode trunk
ip flow monitor NetFlow input
ip flow monitor NetFlow output
interface TenGigabitEthernet1/1/2
switchport trunk encapsulation dot1q
switchport mode trunk
ip flow monitor NetFlow input
ip flow monitor NetFlow output

The 3KX module also includes support for Cisco’s Smart Logging and Telemetry.

Cisco Smart Logging and Telemetry (SLT): This new technology exports NetFlow messages for traffic that is associated to a specific event on a switch (for example, an event triggered by an ACL-permitted or -denied packet).

Flexible NetFlow support….  Smart Logging and Telemetry support….  All you need now is a NetFlow Analyzer that supports FNF and SLT and provides in-depth NetFlow reporting and your Catalyst 3750-X has more than doubled in value.

Is this something you’re interested in?   Let us know what you think.


Joanne Ghidoni
Sr. Solutions Engineer

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3 Responses to “Cisco 3750-X NetFlow Support”

  1. NetFlow Support: Cisco 45xx-E, 2960, 3560, 3750 - NetFlow & sFlow Network Monitoring - Systrax Says:

    [...] last month, I blogged about NetFlow support for the Cisco 3750-X with the 3KX module, not realizing it also applies to the 3560-X model as [...]

  2. Jay Duff Says:

    I have a 3560-X with the 3KX-NM-1G (4x 1GB SFP) module installed, running (C3560E-UNIVERSALK9-M), Version 12.2(55)SE3, and these commands are not available. Since you’re referring to 10gb interfaces, I’m guessing you ran with eh 3KX-NM-10G. Perhaps the 10G has features the 1G does not. I have to say, there are a lot of limitations on the 3560-X, and we are sending ours back.

  3. Says:

    Hi Jay,

    The NetFlow features are only available in the service module C3KX-SM-10G.

    – Tom

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