sFlow¶

sFlow is a technology for monitoring traffic in data networks containing switches and routers. It consists of an sFlow Agent running on the router, and a central sFlow Collector.

The sFlow Agent uses sampling technology to capture traffic statistics from the device it is monitoring. sFlow Datagrams are used to immediately forward the sampled traffic statistics to an sFlow Collector for analysis.

More information is available in RFC 3176 and sflow.org.

To configure sFlow you need to specify the collector endpoint and which interfaces will be polled.

Note

The sFlow module communicates locally with the fast path through the sflow-port, on the localhost address. This behavior requires allowing input traffic on the sflow-port of the system-loopback interface when the fast-path firewall / firewall and sFlow modules are enabled in the same VRF.

Warning

The sFlow module only monitors the packets processed by the fast path.

For each interface, you can tune the sampling interval or let the system choose a value according to the speed of interface.

Configuration example:

vsr running config# vrf main sflow
vsr running sflow# sflow-collector 10.0.0.3 port 6343
vsr running sflow# sflow-interface eth1
vsr running sflow# sflow-sampling speed 10G rate auto
vsr running sflow# commit

To display the sFlow state:

vsr running config# show state vrf main sflow
sflow
    sflow-collector 10.0.0.3 port 6343
    enabled true
    sflow-interface eth1
    sflow-port 36343
    polling disabled
    sflow-sampling speed other rate auto
    sflow-sampling speed 100M rate auto
    sflow-sampling speed 1G rate auto
    sflow-sampling speed 10G rate auto
    sflow-sampling speed 40G rate auto
    ..

The same configuration can be made using this NETCONF XML configuration:

vsr> show config xml absolute vrf main sflow
<config xmlns="urn:6wind:vrouter">
  <vrf>
    <name>main</name>
    <sflow xmlns="urn:6wind:vrouter/sflow">
      <enabled>true</enabled>
      <polling>disabled</polling>
      <sflow-port>36343</sflow-port>
      <sflow-collector>
        <address>10.0.0.3</address>
        <port>6343</port>
      </sflow-collector>
      <sflow-interface>
        <name>eth1</name>
      </sflow-interface>
      <sflow-sampling>
        <speed>10G</speed>
        <rate>auto</rate>
      </sflow-sampling>
    </sflow>
  </vrf>
</config>