Configuring sFlow on switches

[DaHawks]

All,

Few questions regarding sFlow...

We have a bunch of random ProCurve switches... some 4000m, some 2900-24G/48G, and 5406zl... We are evaluating some monitoring software (servers, switches, apps, etc). One of the features we are looking at is the sFlow management / dash (actually provided by Scrutinizer).

I am curious though... is there a good way to determine how much and how often I should have the agent on the switches collect and send flow data to the management station? Not sure if there is a generic rule of thumb?

Thanks,

David

[netvis]

David,

The 4000m predates sFlow, supporting the older HP Extended RMON protocol instead:

HP Extended RMON switches

The 2900 series and 5400 series support sFlow:

HP sFlow switches

Both XRMON and sFlow are sampling technologies. The following article includes rules of thumb that provide a good starting point for setting the sampling rates:

Sampling rates

You mention that you are also interested in monitoring servers. The sFlow standard was recently extended to include server monitoring. You might want to try installing Host sFlow agents on your servers. The free sFlowTrend tool supports Host sFlow, see sFlowTrend adds server performance monitoring for some examples.

Finally, if you are interested in an appliance solution that supports XRMON and sFlow from switches and servers, you might want to take a look at Traffic Sentinel on the HP Services zl Module.

Regards,

Peter

[Helper]

Hi,

A good source of information found here, http://www.inmon.com/products/sFlowTrendHelp.php :

Appendix C. Recommended sampling rates

Table C.1, “Recommended sampling rates” gives the recommended packet sampling rates for sFlow for different interface speeds and traffic levels.

Table C.1. Recommended sampling rates

ifSpeed Low Medium High

10Mb/s 64 128 256

100Mb/s 128 256 512

1Gb/s 256 512 1024

10Gb/s 512 1024 2048

Low, medium and high traffic levels are usually found in the following situations:

Low administrative office environment. Medium typical mixed use environment with file servers and web browsing. High computing clusters, large ISP backbone/hosting.