What is a Proxy or Forwarding server?
RADIUS packet submitted by a client may go directly to the authenticating or accounting server. In many cases the RADIUS packets are sent to an aggregating server that distributes the packets to other servers. This facilitates customer roaming whereby someone may travel and yet use the same final authenticating server while using local aggregating RADIUS servers provided by other ISP’s. The proxy server uses the realm information to direct the packet to another server. This server may be another in a chain of proxy servers or the final authenticator or accounting server. The proxy server must re-encode some attributes using the shared secret of the source of the packet and the shared secret of the destination server.
