Thanks yao guoxian,Mike Mitchell, But it looks to fork(using exec section of radiusd.conf) new processes each time. Using rlm_example($FREERADIUSHOME/src/modules/rlm_example) works fine. I have just replaced the 'example' to 'sync' (the name i chose for my module) in the directory name and all the files inside,-Entered into the directory. I have done some DEBUG("Start Authentication "); So that I understand what it actually does. The compile time configuration is done by, shell < ./configure command. Then I done, shell < make shell < make install I have also made some change in modules section modules{ .... sync { } .... .... } Is it good? I donot know.Some other changes have also be made. authorize{ .... sync .... } authencate{ .... sync .... } accounting{ .... sync .... } At last it works fine. Just donot authenticate the NAS. I think i should work with the attributes (for specific NAS) for replying. Do not know details about authType. Is it make any problem for me? I think i can use mysql-client library to connect local mysql server in it. I have not yet tryed it. I think it needs mysql_client lib to be linked or I include the source. I have done it in a standalone server. But the question is, if freeradius is using threads. And if so what should be done to take care of that. Good Luck -- Kamanashis Roy -- Using Opera's revolutionary e-mail client: http://www.opera.com/mail/