Posted Tue, 20 Sep 2016 19:23:23 GMT by Mark Brown

I recently migrated from running InterMapper on Mac OS X to a RHEL 7 VM.

It appears that IM is incorrectly reporting short term packet loss.  For many systems I'm monitoring (simple ping probe) -- it shows packet loss as high as 50%.  It didn't show this when the same map was running on the Mac.  I've verified there is indeed no measurable packet loss by SSH'ing into the VM and running MTR continuously against several of the hosts IM thinks it's seeing packet loss on.  Zero dropped packets after full hour of running MTR.

Anyone else seeing this issue?

Cheers,

M

Posted Thu, 20 Jul 2017 15:42:47 GMT by Steve Vold

I was asking development about this and one of them made some kernel changes and just finished testing them.

 

Can you review the kernel parameters?

 

sysctl net.ipv4.ip_local_port_range

sysctl net.ipv4.tcp_fin_timeout

 

Then reset them like this:

 

sudo sysctl net.ipv4.ip_local_port_range="15000 61000"

sudo sysctl net.ipv4.tcp_fin_timeout=30

 

 

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