Freeradius2 Accounting secret

[Adrian Hall]

Hello, I have configured Freeradius2 with MySQL and also setup DaloRadius.
I am using it to authenticate PPPoE requests from a Pfsense firewall box.

I have set the shared secret for the Authentication side of things, however 
I keep getting the following error:

Received Accounting-Request packet from client with invalid signature! 
(Shared secret is incorrect.) Dropping packet without response.

Where do I set the shared secret in freeradius2 config for the accounting 
side?

thanks,

Regards,
Adrian Hall.