I updated NAS table,set type to 'livingston', it seemed the Freeradius server has recogenized the nas client. However, another mistake:' MYSQL check_error: 2013, returning SQL_DOWN 'appears,the following are the complete error message: rad_recv: Access-Request packet from host 202.117.15.164:3735, id=17, length=45 User-Name = "barny" User-Password = "betty" Processing the authorize section of radiusd.conf modcall: entering group authorize for request 3 modcall[authorize]: module "preprocess" returns ok for request 3 modcall[authorize]: module "chap" returns noop for request 3 modcall[authorize]: module "mschap" returns noop for request 3 rlm_realm: No '@' in User-Name = "barny", looking up realm NULL rlm_realm: No such realm "NULL" modcall[authorize]: module "suffix" returns noop for request 3 rlm_eap: No EAP-Message, not doing EAP modcall[authorize]: module "eap" returns noop for request 3 radius_xlat: 'barny' rlm_sql (sql): sql_set_user escaped user --> 'barny' radius_xlat: 'SELECT id, UserName, Attribute, Value, op FROM radcheck WHERE Username = 'barny' ORDER BY id' rlm_sql (sql): Reserving sql socket id: 1 rlm_sql_mysql: query: SELECT id, UserName, Attribute, Value, op FROM radcheck WHERE Username = 'barny' ORDER BY id rlm_sql_mysql: MYSQL check_error: 2013, returning SQL_DOWN rlm_sql (sql): Attempting to connect rlm_sql_mysql #1 rlm_sql_mysql: Starting connect to MySQL server for #1 rlm_sql (sql): Connected new DB handle, #1 rlm_sql_mysql: query: SELECT id, UserName, Attribute, Value, op FROM radcheck WHERE Username = 'barny' ORDER BY id rlm_sql_mysql: MYSQL check_error: 2013, returning SQL_DOWN rlm_sql (sql): failed after re-connect rlm_sql_getvpdata: database query error rlm_sql (sql): SQL query error; rejecting user rlm_sql (sql): Released sql socket id: 1 modcall[authorize]: module "sql" returns fail for request 3 modcall: group authorize returns fail for request 3 Finished request 3 Going to the next request --- Walking the entire request list --- Waking up in 6 seconds... --- Walking the entire request list --- Cleaning up request 3 ID 17 with timestamp 4429e5be Nothing to do. Sleeping until we see a request. Dose someone meet the same problem? Appreciate any suggestions.