On Jan 13, 2015, at 8:26 AM, Sourabh Pandit <sourabh.pandit.elists@gmail.com> wrote:

I am using freeradius 2.1.12. For this example consider the following scenario Radius

1. radius server is running on IP 192.168.48.76. 2. radius is using mysql for authentication. 3. A user UserA is in the blocked list when we begin. 4. Process Proc1 is running on 192.168.48.54 5. Process Proc2 is running on 192.168.48.59, listening on port 20000 6. Proc1 and Proc2 do not know about each other at all. I mean they do not even know if another process even exists

RADIUS has nothing to do with processes. It only knows about IPs and shared secrets.

I would appreciate if some one could tell me the following.

1. If process Proc1 wants to remove the UserA form the blocked list by sending a request to the radius server. 1. Can the radius server generate a COA message that goes to Proc2 on port 2000 and not to the Proc1?

You would use radclient to send this message.

2. Is radclient the vehicle to be used by Proc1 to initiate the change in the user group for User A in this case?

radclient sends RADIUS packets.

2. If the above is not possible, let's say the process Proc1 removes the user UserA from the blocked list by manipulating the sql table directly.

That works, too.

1. Can the radius server generate a COA message that goes to Proc2 on port 2000 and not to the Proc1?

You use radclient to generate RADIUS packets.

If it is possible, please point me in the right direction.

All of the CoA configuration, including destination ports, is documented in the server configuration. Alan DeKok.