[ixpmanager] SFLOW Under Reporting?

[Nick Hilliard (INEX)]

Ian Chilton via ixpmanager wrote on 22/06/2023 10:54:
> How close are your MRTG reported traffic levels and that of sflow? (and 
> what switch vendor are you using?)

haven't measured for the Arista platform, but we benchmarked against 
Extreme and Brocade previously, and after some tweaking, got the two 
styles of graph to within ~5% of each other. This depended on software 
version and a variety of other things.

There are several things that can cause discrepancies, e.g. sample rate 
limiting, busy switch CPU, hardware stuff, hardware-to-switch NOS 
interaction. Also, some operating systems measure l3 throughput, others 
l2, so you're not necessarily even measuring the same thing.

And switch configuration: if you're missing sflow stats collection on 
any switch port config, then that will impact things.

Nick