【環境說明】
伺服器版本 redhat5.3
mysql版本 mysql5.6.22freeradius版本 2.1.12
【問題描述】
配置好freeradius的sql.conf中的資料庫位址，以及登入使用者名稱和密碼後，使用「radiusd -x」除錯模式啟動radius，控制台一直在漫長的輸出嘗試連線mysql的日 志，如下所示：
2014-12-30 09:27:39 debug sql.c 93 - [rlm_sql] starting 0
2014-12-30 09:27:39 info sql.c 54 - [rlm_sql] attempting to connect rlm_sql_mysql #0
2014-12-30 09:27:39 info sql_mysql.c 79 - [rlm_sql_mysql] starting connect to mysql server for #0
2014-12-30 09:27:56 info sql.c 58 - [rlm_sql] connected new db handle, #0
2014-12-30 09:27:56 debug sql.c 93 - [rlm_sql] starting 1
2014-12-30 09:27:56 info sql.c 54 - [rlm_sql] attempting to connect rlm_sql_mysql #1
2014-12-30 09:27:56 info sql_mysql.c 79 - [rlm_sql_mysql] starting connect to mysql server for #1
2014-12-30 09:28:12 info sql.c 58 - [rlm_sql] connected new db handle, #1
2014-12-30 09:28:12 debug sql.c 93 - [rlm_sql] starting 2
2014-12-30 09:28:12 info sql.c 54 - [rlm_sql] attempting to connect rlm_sql_mysql #2
2014-12-30 09:28:12 info sql_mysql.c 79 - [rlm_sql_mysql] starting connect to mysql server for #2
2014-12-30 09:28:28 info sql.c 58 - [rlm_sql] connected new db handle, #2
2014-12-30 09:28:28 debug sql.c 93 - [rlm_sql] starting 3
2014-12-30 09:28:28 info sql.c 54 - [rlm_sql] attempting to connect rlm_sql_mysql #3
2014-12-30 09:28:28 info sql_mysql.c 79 - [rlm_sql_mysql] starting connect to mysql server for #3
2014-12-30 09:28:44 info sql.c 58 - [rlm_sql] connected new db handle, #3
2014-12-30 09:28:44 debug sql.c 93 - [rlm_sql] starting 4
2014-12-30 09:28:44 info sql.c 54 - [rlm_sql] attempting to connect rlm_sql_mysql #4
2014-12-30 09:28:44 info sql_mysql.c 79 - [rlm_sql_mysql] starting connect to mysql server for #4
2014-12-30 09:29:00 info sql.c 58 - [rlm_sql] connected new db handle, #4
2014-12-30 09:29:00 debug sql.c 93 - [rlm_sql] starting 5
2014-12-30 09:29:00 info sql.c 54 - [rlm_sql] attempting to connect rlm_sql_mysql #5
2014-12-30 09:29:00 info sql_mysql.c 79 - [rlm_sql_mysql] starting connect to mysql server for #5
2014-12-30 09:29:17 info sql.c 58 - [rlm_sql] connected new db handle, #5
2014-12-30 09:29:17 debug sql.c 93 - [rlm_sql] starting 6
2014-12-30 09:29:17 info sql.c 54 - [rlm_sql] attempting to connect rlm_sql_mysql #6
2014-12-30 09:29:17 info sql_mysql.c 79 - [rlm_sql_mysql] starting connect to mysql server for #6
2014-12-30 09:29:32 info sql.c 58 - [rlm_sql] connected new db handle, #6
2014-12-30 09:29:32 debug sql.c 93 - [rlm_sql] starting 7
2014-12-30 09:29:32 info sql.c 54 - [rlm_sql] attempting to connect rlm_sql_mysql #7
2014-12-30 09:29:32 info sql_mysql.c 79 - [rlm_sql_mysql] starting connect to mysql server for #7
2014-12-30 09:29:48 info sql.c 58 - [rlm_sql] connected new db handle, #7
2014-12-30 09:29:48 debug sql.c 93 - [rlm_sql] starting 8
2014-12-30 09:29:48 info sql.c 54 - [rlm_sql] attempting to connect rlm_sql_mysql #8
2014-12-30 09:29:48 info sql_mysql.c 79 - [rlm_sql_mysql] starting connect to mysql server for #8
2014-12-30 09:30:04 info sql.c 58 - [rlm_sql] connected new db handle, #8
2014-12-30 09:30:04 debug sql.c 93 - [rlm_sql] starting 9
2014-12-30 09:30:04 info sql.c 54 - [rlm_sql] attempting to connect rlm_sql_mysql #9
2014-12-30 09:30:04 info sql_mysql.c 79 - [rlm_sql_mysql] starting connect to mysql server for #9
2014-12-30 09:30:21 info sql.c 58 - [rlm_sql] connected new db handle, #9
2014-12-30 09:30:21 debug sql.c 93 - [rlm_sql] starting 10
2014-12-30 09:30:21 info sql.c 54 - [rlm_sql] attempting to connect rlm_sql_mysql #10
2014-12-30 09:30:21 info sql_mysql.c 79 - [rlm_sql_mysql] starting connect to mysql server for #10
2014-12-30 09:30:37 info sql.c 58 - [rlm_sql] connected new db handle, #10
到99以後提示失敗，經查閱相關資料，進行如下處理即解決問題
【原因分析】
【解決辦法】mysql網域名稱反向解析
【可能存在問題】步驟：
1 vim /usr/my.cnf; mysql5.6.22版的配置檔案在/usr/下，編輯my.cnf，在[mysqld]下增加一行「skip-name-resovle」,儲存退出；
2 重啟mysql；
3 重新啟動radius；
mysql客戶端連線伺服器時，伺服器會對客戶端進行反向網域名稱解析，因此這個是耗時多的原因，取消網域名稱解析以後，mysql的許可權表（user表）中將不能再使用類似localhost之類的主機名，而必須使用ip位址。
---- 《僅供參考》 ----
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