[Xymon] where does xymon client get tcp packet data?

[Richard L. Hamilton]

> On Jan 13, 2016, at 15:38, John Thurston <john.thurston at alaska.gov> wrote:
> 
> On 1/13/2016 11:21 AM, John Thurston wrote:
>> The below relates to linux, xymon 4.3.17
>> 
>> I was going to write a script to collect and report numbers of TCP
>> packet retransmissions. But when I look at the 'trends' for this host, I
>> see there is already a chart for "TCP/IP statistics" which includes
>> "In/Out/Retrans"  - snip -
> 
> Ohhh. I think I see. It probably _is_ lining up with the numbers being reported by nstat. The difficulty is the number is being graphed as packets/second and plotted on the same chart as IN and OUT packets (also being graphed in packets/second). My small number of retransmissions is being lost in the noise of the total volume of packets.
> 
> Is there a way to re-define the graph to display a multiple of the recorded value? Or plot this counter against an alternate y-axis set to a different scale?
> 
> I suppose I could define a new graph to contain only retransmissions so the small number isn't swamped by the general traffic count.
> 
> -- 
>   Do things because you should, not just because you can.


Maybe I'm missing the point, but unless one has a strictly two-host link, full-duplex, both similar (speed, OS), and lightly loaded, retransmissions are _normal_ at a low level.  And if the level is so low relative to traffic that it's invisible, why is the exact level interesting?  Should it become visible, there's still time to worry.

Your signature slogan made me think about that. :-)  Or is this one of those government someone-had-an-idea-that-you-can't-escape things (been there)?