HI Joe,

My ft file is 5 minutes long (the stat interval is 5).
Both my Juniper and Cisco do sampling and packet-interval is 100.

For this case, I need to change the ft file to 15 minutes long? on the other
hand, I am not sure how to calculate the "multipliers".

Regards,
Jacky


On Tue, May 4, 2010 at 9:08 PM, Joe Loiacono <[email protected]> wrote:

>
> When you apply flow-stat to a single ft file, you're getting the average
> rate over the length of time associated with the file. My ft files are
> typically 15 minutes long. If we assume yours are 15 minutes also, you are
> comparing a 15 minute average with an MRTG 5-minute SNMP sample of all bytes
> (including IP and TCP headers.)
>
> Looking at sampling as a possibility, here are the 'multipliers':
>
> 110/0.293 = 375
> 136/0.323 = 421
> 24/0.225 = 107
> 96/1.462 = 66
>
> They're not consistent. But if you create an MRTG number from the average
> of the three readings that make up the 15 minute netflow period, you might
> find a consistent multiplier.
>
> But - you could first just check to see if you're sampling on the Juniper
> :-)
>
> By the way - have you checked out FlowViewer as a web interface to
> flow-tools?
>
> http://ensight.eos.nasa.gov/FlowViewer/
>
> Joe
>
>
>   From: Jacky Chan <[email protected]> To:
> [email protected] Date: 05/04/2010 01:52 AM Subject: [Flow-tools]
> Flow-stat vs MRTG
> ------------------------------
>
>
>
> Dear Sir,
>
> I have flow-tools 0.68 running on a Fedora Core 11 workstation and the
> system collecting flow-data from Juniper and Cisco routers.
>
> I tried obtain the link utilization from the flow-stat output but there is
> big different when compared to MRTG reading.
>
> Example-1
> I have a GE link from my Juniper router to INTERNET upstream-1
> From MRTG, the average input / output speed @ 21:00 are 110Mbps/ 136Mbps.
> From Flow-stat, the input/ output speed @21:00 are 292.6613Kbps/
> 323.1716Kbps.
>
> Example-2
> I have a GE link from my Cisco router to INTERNET upstream-2
> From MRTG, the average input / output speed @ 21:00  are 24Mbps/ 96Mbps.
> From Flow-stat, the input/ output speed @21:00 are 225.0744Kbps/
> 1462.7255Kbps.
>
> Here are the commands I used to obtain the link utilization from the
> flow-data. I did something wrong or misused the flow-stat application?
>
> flow-cat ft-v05-2010-05-03.210000+0800 | flow-filter -e JUNIPER-IP -i116 |
> flow-stat
> flow-cat ft-v05-2010-05-03.210000+0800 | flow-filter -e JUNIPER-IP -I116 |
> flow-stat
> flow-cat ft-v05-2010-05-03.210000+0800 | flow-filter -e CISCO-IP -i13 |
> flow-stat
> flow-cat ft-v05-2010-05-03.210000+0800 | flow-filter -e CISCO-IP -I13 |
> flow-stat
>
>
>  --
> Jacky :)_______________________________________________
> Flow-tools mailing list
> [email protected]
> http://mailman.splintered.net/mailman/listinfo/flow-tools
>
>


-- 
Jacky Chan :)
_______________________________________________
Flow-tools mailing list
[email protected]
http://mailman.splintered.net/mailman/listinfo/flow-tools

Reply via email to