Problem Dude icmp packets

Hello Friends

I’m having problems with my server dude, my devices are showing offline, more when I do the ping test them online. I did the following test from inside the dude put to test devices via icmp, the dude there is a loss, more on the local machine does not lose any packets icmp.

a friend who can help?
problema-dude.jpg

I have not seen anything like it. I have heard of ping flat out not working when the user running the dude is not privileged but not intermittent.