Recently,
we attempted to update the freeradius from version 2.x to 3.2.6.
We copied the existing configuration(clients.conf, radiusd.conf etc) to the freeradius installed on the new Linux system.
In testing, there were no issues with PPP that directly requests authentication from the cpe to the radius server.
However, L2TP authentication that passes through another company’s proxy radius encounters an error.