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

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" I'm specifically looking for TCP retransmission count. This counter does not seem to line up with information being reported by nstat.

What is this built-in test reporting, and from where is it collected?

Do things because you should, not just because you can.

John Thurston 907-465-8591 John.Thurston at alaska.gov Enterprise Technology Services Department of Administration State of Alaska