sflow on HP2848

[Steve Britt]

Andrea,

Although there is a provision in the sFlow specification for providing optional counters that are specific to each VLAN, the ProCurve sFlow implementation does not implement this optional counter group. So, in short, there is no "virtual port" sort of convenient way to monitor a VLAN as there is with a trunk or mesh.

However, VLAN information can be gleaned from the flow samples by decoding the headers and tracking the VLAN information contained within them over a period of time, and then projecting the proportions from the tracked flow samples during the period onto the overall frame and octet counts from that period. At this time, this is really the only means of decoding tagged VLAN data that I am aware of.

SVB

[Joel Thys]

Hi,

Our SFlow collector does not support Sflow V5. How can change the version to version 4.

Up to the HP website, the HP Procurve 2848 supports the RFC 3176. And this RFC includes support for version 4 of Sflow.

Thanks in advance,

Joel

[Jeff Brownell]

What is the problem? You are wanting to change something on the switch or the sflow collector? or ???

[netmon]

Andrea,

We have a number of free tools that you might find helpful for configuring and analyzing sFlow reporting.

The tools are:
1. sflowenable is a command line utility for configuring sFlow on Procurve switches.
2. sFlowTrend is a graphical tool for analyzing and displaying sFlow data and can automatically configure sFlow using the sFlow MIB.
3. sflowtool can convert sFlow into different formats and pretty print sFlow data.

The tools are available at:
http://www.inmon.com/technology/sflowVersion5.php

Peter

[HP Delema]

Hello Friends,

Following the procedure outlined by Jeff Brownell gives our Scrutinizer SFlow collector only counters and whatâ s more, it seems to inexplicably un-configure itself and stop sending anywhere from 1-3 hours after itâ s originally set.

Has anyone else tested his posting?

Mike

[Lei.Ma]

whatever you use HP PCM+ or other sflow collector software you can see the flow about source and destination ip address pairs.

for my personal, i use the SflowTrend to collect the sflow sample.
you can download the software from below website, it's free.

http://www.inmon.com/products/sFlowTrend.php

i hope it's helpful.

ray ma

[MattS_3]

If I have a modular switch, do I need to use, say, port F14 rather than a numbered port? For some reason, I cannot get the commands to work:

Set flow sampling sampling rate to 37 on port F14.
setmib 1.3.6.1.4.1.14706.1.1.5.1.4.11.1.3.6.1.2.1.2.2.1.1.F14.1 -i 37

I get the error: "cannot translate variable"

[MattS_3]

I have 6 modules, the first five of which are the 24-port 10/100 modules.

A1-A24 are 10/100
B1-B24 are 10/100
C1-C24 are 10/100
D1-D24 are 10/100
E1-E24 are 10/100
F1-F24 are 10/100/1000

The port I really care about is F14, so if you count up, it would be port 134. Is this correct?

[beovax]

sorry to be stupid but can some one please explain what the the sampling and pollong does? If I leave the polling disabled I still get results using our analyaser - do I need polling?

also I see about 1500 dropped samples every hour on one of our ports. Sampling rate is set to 80, is this normal?

[netvis]

A sampling rate of 80 is very low (unless you have very little traffic on your network). The following article provides suggested sampling rates for different link speeds and typical traffic levels:
http://blog.sflow.com/2009/06/sampling-rates.html

The sFlow agent performs two types of monitoring: packet sampling for measuring traffic flows and counter polling for monitoring link utilization. If your traffic analyzer doesn't support sFlow counter polling, then you don't need to enable counter polling.

However, to get the most out of sFlow it is worth using an sFlow analyzer that supports all the capabilities of the protocol (packet decoding, counter polling, auto-configuration using sFlow MIB etc). The sFlowTrend application (mentioned earlier on this thread) is free and fully supports the sFlow features on HP switches:
http://www.sflowtrend.com/