On Jun 1, 2017, at 8:06 AM, khouzam yaghi <khouzam.yaghi@gmail.com> wrote:

i am receiving this error from time to time in the radius log

Error: Discarding conflicting packet from client PPPOE1 port 33184 - ID: 1 due to recent request

i searched online and found very old posts about this error, what does it mean? is it something related to the database slow?

Yes.

or broken NAS?

Possibly that, too.

my NAS is a Linux server running accel-ppp as a pppoe-server. is this something related to the NAS itself or to my configuration with freeradius? also what does this error means?

It means that something is blocking there server. To see what's going wrong, run the server in debugging mode. The default configuration does *not* have this behaviour. Largely because it doesn't talk to databases by default. Alan DeKok.