Hi Luca, well, according to statistics that would be almost accurate (due to the random nature of sflow sampling, e.g. it's not every 50th packet, but out of 50 packets one will be sampled). the way it is right now is just very confusing :) thanks! Regards, Johannes
Am Mittwoch, den 05.11.2008, 15:12 +0100 schrieb Luca Deri: > Hi all > I don't think that changing sampling rate to 1 is the solution. sFlow > by its nature is sampled as you will read here: > http://www.sflow.org/about/sampling_theory.php > > This explains why the figures you see are not 100% accurate. What I > could do in ntop is to scale the figures based on sampling rate you > specify on the switch, but yet this is not a 100% accurate solution > > Cheers Luca > > On Nov 3, 2008, at 5:26 PM, jr wrote: > > > Patrick, > > this is done on the switch, if it supports it. > > My switches (HP ProCurve) won't let me sample any more often than > > every > > 20st packet :/ > > regards, > > johannes > > > > Am Montag, den 03.11.2008, 08:18 -0800 schrieb Patrick Topping: > >> Gerhard, > >> > >> I am suffering from the same issue.... Where did you make the change > >> for this --> I've configured the rate to 1 on all ports. > >> > >> Thanks in advance. > >> > >> -Patrick > >> > >> -------------------------- > >> > >> > >> Gerhard Mourani wrote: > >>> Hello Luca, > >>> > >>>> How did you configure sflow in your foundry? > >>> I've configured the rate to 1 on all ports. After doing this, I > >>> can see > >>> that captured informations are better accurate but not 100%. For > >>> example, if I transfers 100 MB now, I will see around 90 MB. I > >>> think I > >>> cannot do better than that because it use sampling as you said. > >>> > >>> Gerhard, > >>> > >>> Luca Deri wrote: > >>> > >>>> Gerhard > >>>> sflow uses sampling. hence if you send let's say 100 you will see 1 > >>>> using sflow. How did you configure sflow in your foundry? > >>>> > >>>> Luca > >>>> > >>>> On Oct 31, 2008, at 7:33 PM, Gerhard Mourani wrote: > >>>> > >>>> > >>>> > >>>>> Hello List, > >>>>> > >>>>> I've activated the sFlow plugin into my ntop version 3.3.8 to > >>>>> capture > >>>>> and display sFlow data coming from my "Foundry Network FastIron > >>>>> Edge > >>>>> 9604" model. If I check inside the plugin page of sFlow about > >>>>> 'sFlow > >>>>> Interface Statistics' everything are correct and reported data > >>>>> transfers > >>>>> for 'Administrative' or 'Operational' status are ok. But now my > >>>>> problem > >>>>> is when I check inside the ntop web interface and especially about > >>>>> collected data, here the problem is that returned informations > >>>>> about > >>>>> amount of data are wrong, I mean the amount of data doesn't > >>>>> correspond > >>>>> to what have really been transfered. So for example if I > >>>>> transfer 135 > >>>>> MBytes I can only see 295.0 KBytes in ntop. Someone know how to > >>>>> fix > >>>>> this? > >>>>> > >>>>> Thanks for your helps, > >>>>> Gerhard, > >>>>> _______________________________________________ > >>>>> Ntop mailing list > >>>>> Ntop@unipi.it > >>>>> http://listgateway.unipi.it/mailman/listinfo/ntop > >>>>> > >>>>> > >>>> _______________________________________________ > >>>> Ntop mailing list > >>>> Ntop@unipi.it > >>>> http://listgateway.unipi.it/mailman/listinfo/ntop > >>>> > >>>> > >>> _______________________________________________ > >>> Ntop mailing list > >>> Ntop@unipi.it > >>> http://listgateway.unipi.it/mailman/listinfo/ntop > >>> > >>> > >>> > >> _______________________________________________ > >> Ntop mailing list > >> Ntop@unipi.it > >> http://listgateway.unipi.it/mailman/listinfo/ntop > > > > _______________________________________________ > > Ntop mailing list > > Ntop@unipi.it > > http://listgateway.unipi.it/mailman/listinfo/ntop > > _______________________________________________ > Ntop mailing list > Ntop@unipi.it > http://listgateway.unipi.it/mailman/listinfo/ntop _______________________________________________ Ntop mailing list Ntop@unipi.it http://listgateway.unipi.it/mailman/listinfo/ntop
