Error sending request: No valid RADIUS responses received

[Greg Larkins]

>> Using the oPi as the server, I'm getting authentication errors: "Error
>> sending request: No valid RADIUS responses received"

>  Then either the shared secret is wrong, or there are network issues which prevent the two systems from talking;

>>Debug output for the non-working server:
>> ...
>> Failed binding to authentication address * port 1812: Address already in use
>> /etc/freeradius/radiusd.conf[273]: Error binding to port for 0.0.0.0 port
>> 1812

> No, that is NOT what we need.

>  We need to see what happens when the server receives a packet.

> Stop the background process, and run it in debug mode.  Ensure that the server receives >packets.  THAT debug output is useful.

>  Alan DeKok.

I got it working. Looking at the debug output from the working server
are the lines:

"rlm_sql (sql): Read entry
nasname=192.168.225.1,shortname=pfSense,secret=mysecret
rlm_sql (sql): Adding client 192.168.225.1 (pfSense, server=<none>) to
clients list"

So in the clients.conf file on the non-working server I added the lines:

client 192.168.225.1 {
        secret          = mysecret
        shortname       = pfsense
}

And re-started the server, and now it works.

I don't understand why these lines are absent from my working server
clients.conf file and yet it works. Obviously the NAS info must be
present somewhere else, but where?