【Oracle問題集3】ORA-12543: TNS:destination host unreachable

說明：【oracle問題集】是博主平時操作數據庫遇到的問題以及解決方案。

執行語句：表示操作數據庫過程

出錯現象：表示操作數據庫過程出現錯誤現象

出錯原因：表示出現錯誤的原因

解決方法：表示解決錯誤的方法

相關知識：表示與這個主題相關的知識

====================================================================

執行語句：

連接數據庫：connect sys/[email protected]/orcl as sysdba

出錯現象：

       ORA-12543: TNS:destination host unreachable

錯誤原因：

sqlnet.ora文件中的NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)，添加ezconnect參數值，所以如果指定數據庫實例，必須要跟上主機ip地址。請參考【Easy Connect Naming】。因此正確的寫法是：CONNECT username/password@host[:port][/service_name]

例如connect sys/[email protected]/orcl as sysdba

解決方法：

連接數據庫時需要指定主機ip地址：connect sys/[email protected]/orcl as sysdba

相關知識：

             以下知識來源於oracle官方文檔

Naming Method	Description
Local Naming	Resolves a net service name stored in a tnsnames.ora file stored on a client Local naming is most appropriate for simple distributed networks with a small number of services that change infrequently. See Also: "Configuring the Local Naming Method"
Directory Naming	Resolves a database service name, net service name, or net service alias stored in a centralized LDAP-compliant directory server See Also: "Configuring the Directory Naming Method"
Easy Connect Naming	Enables clients to connect to a database server without any configuration. Clients use a connect string for a simple TCP/IP address, consisting of a host name and optional port and service name: CONNECT username/password@host[:port][/service_name] This method is recommended for simple TCP/IP environments. See Also: "Using the Easy Connect Naming Method"
External Naming	Resolves service information stored in an a third-party naming service See Also: "Configuring External Naming Methods"

相關監聽配置測試工具命令：lnsrctl、tnsping

listener.ora文件內容：

# listener.ora Network Configuration File: /home/oracle/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora

# Generated by Oracle configuration tools.

SID_LIST_LISTENER=

  (SID_LIST=

    (SID_DESC=

     (SID_NAME=orcl)

     (ORACLE_HOME=/home/oracle/app/oracle/product/11.2.0/dbhome_1)

    )

   )

LISTENER =

  (DESCRIPTION_LIST =

    (DESCRIPTION =

      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))

      (ADDRESS = (PROTOCOL = TCP)(HOST=192.168.135.243)(PORT = 1521))

    )

  )

ADR_BASE_LISTENER = /home/oracle/app/oracle

tnsnames.ora文件內容

# tnsnames.ora Network Configuration File: /home/oracle/app/oracle/product/11.2.0/dbhome_1/network/admin/tnsnames.ora

# Generated by Oracle configuration tools.

ORCL =

  (DESCRIPTION =

    (ADDRESS = (PROTOCOL = TCP)(HOST =192.168.135.243)(PORT = 1521))

    (CONNECT_DATA =

      (SERVER = DEDICATED)

      (SERVICE_NAME = orcl.192.168.132.243)

    )

  )

sqlnet.ora

# sqlnet.ora Network Configuration File: /home/oracle/app/oracle/product/11.2.0/dbhome_1/network/admin/sqlnet.ora

# Generated by Oracle configuration tools.

NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)

ADR_BASE = /home/oracle/app/oracle