On mainline images provided by Olimex, a standard user can not use the ping command : it always ends up with the following message :
Quoteping: socket: Operation not permitted
Running the same ping command as root (or with sudo) works as expected.
I had mentioned this problem in June 2020 :
and got this answer from Olimex a few days later :
Quoteour developers work on this, there will be fix soon
Well, this problem is still there with latest images from Olimex (currently A64-OLinuXino-buster-minimal-20201217-194545.img)
The workaround mentioned in https://github.com/MichaIng/DietPi/issues/1012 seems to work