Question regarding shared secret ..!!

[amekrani]

Hi All,
        I would like to as a general question about RADIUS Server.

Case 1:
N1=NAS Client
R1=RADIUS Server

N1<shared secret=1>                        R1<shared secret =2>

Then should it be the case that there should be a silent discard at R1 for a request. or R1 should respond to N1 and N1 should check the authenticator and on the mismatch the packet should be dropped at N1 while returning.

Case 2:

N1=NAS Client
P1=Proxy RADIUS Server
R1=RADIUS Server

N1<shared secret=1>                        P1<shared secret =1>                         R1<shared secret =2>

Then in this case should the packet should be dropped at R1 or it should be retuned from R1 to P1 and then dropped.

What should be the answer for case 1 and 2 and WHY.

Your Answers are valuable for me.

Regards,
Asif Mekrani