[20221012]TNS-12543 TNSdestination host unreachable.txt[亲测有效]

–//今天尝试本机连接测试库,出现如下问题.sqlplus报ORA-12543: TNS:destination host unreachable错误.

R:>tnsping 78

TNS Ping Utility for 64-bit Windows: Version 12.2.0.1.0 – Production on 12-OCT-2022 09:37:50

Copyright (c) 1997, 2016, Oracle.  All rights reserved.

Used parameter files:

E:apporacleproduct12.2.0dbhome_1NETWORKADMINsqlnet.ora

Used EZCONNECT adapter to resolve the alias

Attempting to contact (DESCRIPTION=(CONNECT_DATA=(SERVICE_NAME=))(ADDRESS=(PROTOCOL=TCP)(HOST=0.0.0.78)(PORT=1521)))

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

TNS-12543: TNS:destination host unreachable

R:>tnsping 192.168.100.78

TNS Ping Utility for 64-bit Windows: Version 12.2.0.1.0 – Production on 12-OCT-2022 09:38:12

Copyright (c) 1997, 2016, Oracle.  All rights reserved.

Used parameter files:

E:apporacleproduct12.2.0dbhome_1NETWORKADMINsqlnet.ora

Used EZCONNECT adapter to resolve the alias

Attempting to contact (DESCRIPTION=(CONNECT_DATA=(SERVICE_NAME=))(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.100.78)(PORT=1521)))

OK (20 msec)

–//如果我使用78时,oracle把它当作IP地址,变成了0.0.0.78.我检查tnsnames.ora文件,发现存在定义.

78 =

  (DESCRIPTION =

    (ADDRESS_LIST =

      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.100.78)(PORT = 1521))

    )

    (SDU = 32768)

    (CONNECT_DATA =

      (SERVER = DEDICATED)

      (SERVICE_NAME = book)

    )

  )

–//尝试另外的tnsnames别名78x.

R:>tnsping 78x

TNS Ping Utility for 64-bit Windows: Version 12.2.0.1.0 – Production on 12-OCT-2022 09:43:17

Copyright (c) 1997, 2016, Oracle.  All rights reserved.

Used parameter files:

E:apporacleproduct12.2.0dbhome_1NETWORKADMINsqlnet.ora

Used TNSNAMES adapter to resolve the alias

Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.100.78)(PORT = 1521))) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = book) (UR = A)))

OK (20 msec)

–//使用78x连接正常,仅仅有点慢.

–//问题在于我以前使用sqlplus连接是正常的,不会报错.而现在报错.

R:>sqlplus -s -l scott/book@78

ERROR:

ORA-12543: TNS:destination host unreachable

SP2-0751: Unable to connect to Oracle.  Exiting SQL*Plus

–//使用Net Manager打开tnsnames.ora文件正常,说明文件没有问题.

–//进入E:apporacleproduct12.2.0dbhome_1 etworkadmin目录观察,发现

E:apporacleproduct12.2.0dbhome_1 etworkadmin>dir

 驱动器 E 中的卷是 app

 卷的序列号是 DACE-DD40

 E:apporacleproduct12.2.0dbhome_1 etworkadmin 的目录

2022/10/12  09:43    <DIR>          .

2022/10/12  09:43    <DIR>          ..

2020/03/11  17:30               733 listener.ora

2018/11/05  09:10    <DIR>          sample

2022/09/02  09:43               571 sqlnet.ora

2020/03/11  17:30            19,311 tnsnames – 副本.ora

2021/05/19  10:36            19,788 tnsnames.ora

               4 个文件         40,403 字节

               3 个目录 36,502,573,056 可用字节

–//sqlnet.ora 2022/9/2修改过.

R:>cat e:sqlnet.ora

# sqlnet.ora Network Configuration File: E:apporacleproduct12.2.0dbhome_1 etworkadminsqlnet.ora

# Generated by Oracle configuration tools.

SQLNET.AUTHENTICATION_SERVICES= (NTS)

NAMES.DIRECTORY_PATH= (EZCONNECT,TNSNAMES,HOSTNAME)

#SECURE_REGISTER_LISTENER= (TCP)

#USE_DEDICATED_SERVER=on

#NAMES.DIRECTORY_PATH= (HOSTNAME)

SQLNET.ALLOWED_LOGON_VERSION_SERVER=10

SQLNET.ALLOWED_LOGON_VERSION_CLIENT=10

#SEC_USER_UNAUTHORIZED_ACCESS_BANNER

#DEFAULT_SDU_SIZE=65535

#SQLNET.ENCRYPTION_CLIENT = rejected

#SQLNET.ENCRYPTION_TYPES_CLIENT =3des168

–//好像也没有怎么问题.难道我以前从来没有遇到过呢.改名sqlnet.ora为sqlnet.orax.

d: otes>tnsping 78

TNS Ping Utility for 64-bit Windows: Version 12.2.0.1.0 – Production on 12-OCT-2022 10:04:32

Copyright (c) 1997, 2016, Oracle.  All rights reserved.

Used parameter files:

Used TNSNAMES adapter to resolve the alias

Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.100.78)(PORT = 1521))) (SDU = 32768) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = book)))

OK (20 msec)

–//说明sqlnet.ora文件修改存在问题.我重新使用Net Manager配置,文件保存后内容如下:

# sqlnet.ora Network Configuration File: E:apporacleproduct12.2.0dbhome_1NETWORKADMINsqlnet.ora

# Generated by Oracle configuration tools.

#SECURE_REGISTER_LISTENER= (TCP)

#USE_DEDICATED_SERVER=on

#NAMES.DIRECTORY_PATH= (HOSTNAME)

#SQLNET.ALLOWED_LOGON_VERSION_SERVER=10

#SQLNET.ALLOWED_LOGON_VERSION_CLIENT=10

#SEC_USER_UNAUTHORIZED_ACCESS_BANNER

#DEFAULT_SDU_SIZE=65535

#SQLNET.ENCRYPTION_CLIENT = rejected

#SQLNET.ENCRYPTION_TYPES_CLIENT =3des168

SQLNET.AUTHENTICATION_SERVICES= (NTS)

NAMES.DIRECTORY_PATH= (EZCONNECT, TNSNAMES, HOSTNAME)

DIAG_ADR_ENABLED = OFF

–//问题依旧.我把NAMES.DIRECTORY_PATH顺序修改如下:

NAMES.DIRECTORY_PATH= (TNSNAMES, HOSTNAME, EZCONNECT)

–//问题消失,这样优先选择TNSNAMES.实际上问题在于EZCONNECT写在前面相当于把78当作IP地址.

–//实际上我还发现如果修改如下

NAMES.DIRECTORY_PATH= (EZCONNECT , TNSNAMES, HOSTNAME)

–//注意EZCONNECT与逗号(,)之间存在空格.就可以通过.实际上这样EZCONNECT ,这样写错误的,oracle给配置埋了一个坑.

–//所以不建议维护时手工修改该文件,要注意一些细节.

–//我最终修改如下:

# sqlnet.ora Network Configuration File: E:apporacleproduct12.2.0dbhome_1NETWORKADMINsqlnet.ora

# Generated by Oracle configuration tools.

#SECURE_REGISTER_LISTENER= (TCP)

#USE_DEDICATED_SERVER=on

#NAMES.DIRECTORY_PATH= (HOSTNAME)

SQLNET.ALLOWED_LOGON_VERSION_SERVER=10

SQLNET.ALLOWED_LOGON_VERSION_CLIENT=10

#SEC_USER_UNAUTHORIZED_ACCESS_BANNER

#DEFAULT_SDU_SIZE=65535

#SQLNET.ENCRYPTION_CLIENT = rejected

#SQLNET.ENCRYPTION_TYPES_CLIENT =3des168

SQLNET.AUTHENTICATION_SERVICES= (NTS)

NAMES.DIRECTORY_PATH= (TNSNAMES, HOSTNAME, EZCONNECT)

#NAMES.DIRECTORY_PATH= (EZCONNECT, TNSNAMES, HOSTNAME)

DIAG_ADR_ENABLED = OFF

–//如果你遇到上面的情况如何解决呢?很简单,你可以尝试在后面加入一个点(.),看看是否可以通过.测试如下:

–//设置NAMES.DIRECTORY_PATH= (EZCONNECT, TNSNAMES, HOSTNAME)的情况下:

R:>sqlplus -s -l scott/book@78 @ ver1

ERROR:

ORA-12543: TNS:destination host unreachable

SP2-0751: Unable to connect to Oracle.  Exiting SQL*Plus

R:>sqlplus -s -l scott/book@78. @ ver1

PORT_STRING                    VERSION        BANNER

—————————— ————– ——————————————————————————–

x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 – 64bit Production

quit

–//最后还是建议还是EZCONNECT放在后面,不然连接确实有点慢.