Hi everyone, Need help for modifying the radius client or updating for CHAP authentication, Modified the below attribute, instead of PW_USER_PASSWORD to PW_CHAP_PASSWORD, but its rejecting please do know if i'm wrong or/and have to take care of any other aspect. With PAP(PW_USER_PASSWORD)it works fine. Have verified by command line it works fine, $echo "User-Name=steve,CHAP-Password=testing,Framed-Protocol=PPP" | radclient localhost:1812 auth testing123 ---Code snippet-- /*if (rc_avpair_add(rh, &send, PW_USER_PASSWORD, passwd, -1, 0) == NULL) return ERROR_RC;*/ //VALUE_PAIR if (rc_avpair_add(rh, &send, PW_CHAP_PASSWORD, passwd, -1, 0) == NULL) return ERROR_RC; /* * Fill in Service-Type */ service = PW_AUTHENTICATE_ONLY; if (rc_avpair_add(rh, &send, PW_SERVICE_TYPE, &service, -1, 0) == NULL) return ERROR_RC; result = rc_auth(rh, 0, send, &received, msg); --End code snippet -- Thanks in Advance -Santosh Cheers, Santosh Kumar Sr Software Engineer Cell:09881481468 Computers can never replace human stupidity.