Tuesday, June 23, 2009

sFlow MIB

Configuring switches through the switch command line interface (CLI) can be complex and time consuming, especially when monitoring needs to be configured on every switch in order to achieve network-wide visibility.

The sFlow MIB provides a way for an sFlow analysis application to use SNMP to automatically configure sFlow settings on the switches that it wants to monitor. Since the sFlow MIB is an optional part of the sFlow standard, not all sFlow capable switches can be configured using SNMP. However, HP ProCurve and Alcatel-Lucent switches support the sFlow MIB making it easy to quickly try out sFlow monitoring using the free sFlowTrend application. The screen capture above shows the sFlowTrend setting needed to enable SNMP configuration of sFlow.

Many traffic analyzers that claim sFlow support do not support the sFlow MIB. If you have switches that support the sFlow MIB, then selecting an analyzer that supports the sFlow MIB will ensure a successful deployment.

Future posts on this blog will describe the configuration commands needed to enable sFlow on additional vendor's switches.


  1. Hello Peter,

    Great topic. Any chance you could layout all of the OIDs necesssary to configure sFlow via SNMP? As well as the steps?
    For Example:
    * Display the current settings: several options are displayed.
    * The HP used to require the IP be configured in HEX!
    setmib sFlowRcvrAddress.1 –o OA020165
    * Configure the receiver port:
    setmib sFlowRcvrPort.1 –i 6343
    * Do you still have to set a receiver and a timeout. Most people really don't like this shutting off automatically.
    setmib sFlowRcvrOwner.1 -D scrut sFlowRcvrTimeout.1 -i 100000000

    When using SNMP and an OID set tool, you have to configure the sample rate on each individual interface, then enable it on each individual interface. I think counters have to be enabled on each individual interface as well. Please correct me.

    Yes, I've spent many an hour on this topic! :)

    Can you make a document available that explains how to configure all this correctly?

    Thank you for a great topic.

    Michael Patterson

  2. Michael,

    Your questions suggest that you are trying to configure sFlow manually using the switch CLI and the sFlow MIB. The sFlow MIB should never be used manually.

    The sFlow MIB is a programmatic API that enables "plug and play" discovery and configuration of sFlow monitoring. The MIB makes sFlow monitoring very simple for the end user. Instead of having to configure each switch through the CLI, the traffic analysis application automatically discovers and configures sFlow devices.

    If Plixer is interested in adding support for the sFlow MIB to its products, developer information and tools are available at sFlow.org