21 has been configured as the RADIUS NAS- IP- Address attribute: radius- server attribute 4 10. 21 radius- server host 10.
10 aut: IP address assignment to pppoe clients - Radius or DHCP AVPair are sent to the LNS. LNS will process them and send the right information to the CPE, in a PPP packet.
There is no data source to use to populate static entries for each unit, so I would prefer each unit to get an IP assigned from a pool first time it connects and then keep that address. Assign the custom internal- user attribute with the static IP address.
Assign a RADIUS authorization profile with advanced attributes settings to assign Radius: Framed- IP- Address with the value from the custom attribute.