Configuring sFlow on an HP 2920 (J9726a)

Version 1

    The HP 2920 series switches are sFlow capable, but due to a firmware issue do not support sFlow while the OOBM (Out-of-Band-Management) port is enabled. It wasn't until a few hours on the phone with HP, them having to test it in their lab, and then calling me the next day that this was discovered. The configuration instructions for Procurves in the NTA guide are outdated.

     

    1. OOBM has to be disabled, at least until HP releases a firmware update that fixes this. If you configure sFlow with the OOBM port enabled, it will seem to work, but no flows will be sent. The following command disables OOBM (you should be logged in from the console port):

      no oobm ip address

    2. You'll need to setup the management IP address on a VLAN, in my flat networking environment I used VLAN 1. Whatever you do, the sFlow has to be able to get to your NTA server with the VLAN it's a member of.

      vlan 1 ip address 10.100.64.201/21

    3. Now you need to point sFlow to your Orion server. The default port (I believe) is 2055

      sflow 1 destination 10.100.64.135 2055

    4. And finally, you have to setup the interface you want to pull from, and sampling and polling rates/intervals. The sampling rate can be 50-16441700. The lower the number, the more packets sampled. In my case, I'm sampling from interface 23 at a rate of 1-in-50, with a polling interval of 20 seconds

      sflow 1 sampling 23 50
      sflow 1 polling 23 20

    5. That's it, just make sure you do a write memory so that it persists reboots.

     

    This is my first post on Thwack. I hope this is helpful and saves somebody else a lot of time. I'd be nice if the configuration instructions were updated from those horrible setmib steps.