TNS-12171: TNS could not resolve connect identifier: string

Mehmet Salih Deveci

5 years ago

Hi,

Sometimes You can get “TNS-12171: TNS:could not resolve connect identifier: string ” error.

Details of error are as follows.

TNS-12171: TNS:could not resolve connect identifier: string

Cause: A connection to a database or other service was requested using a connect identifier,

and the connect identifier specified could not be resolved into a connect descriptor

using one of the naming methods configured. For example, if the type of connect identifier

used was a net service name then the net service name could not be found in a naming method

repository, or the repository could not be located or reached.

– If you are using local naming (TNSNAMES.ORA file):

– Make sure that “TNSNAMES” is listed as one of the values of the NAMES.DIRECTORY_PATH parameter in the Oracle Net profile (SQLNET.ORA)

– Verify that a TNSNAMES.ORA file exists and is in the proper directory and is accessible.

– Check that the net service name used as the connect identifier exists in the TNSNAMES.ORA file.

– Make sure there are no syntax errors anywhere in the TNSNAMES.ORA file. Look for unmatched parentheses or stray characters. Errors in a TNSNAMES.ORA file may make it unusable.

– If you are using directory naming:

– Verify that “LDAP” is listed as one of the values of the NAMES.DIRETORY_PATH parameter in the Oracle Net profile (SQLNET.ORA).

– Verify that the LDAP directory server is up and that it is accessible.

– Verify that the net service name or database name used as the connect identifier is configured in the directory.

– Verify that the default context being used is correct by specifying a fully qualified net service name or a full LDAP DN as the connect identifier

– If you are using easy connect naming:

– Verify that “EZCONNECT” is listed as one of the values of the NAMES.DIRETORY_PATH parameter in the Oracle Net profile (SQLNET.ORA).

– Make sure the host, port and service name specified are correct.

– Try enclosing the connect identifier in quote marks. See the Oracle Net Services Administrators Guide or the Oracle operating system specific guide for more information on naming.

To solve this error, add the following parameters to the sqlnet.ora file under $ORACLE_HOME/network/admin.

NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)
SQLNET.INBOUND_CONNECT_TIMEOUT=360
SQLNET.RECV_TIMEOUT=10
SQLNET.SEND_TIMEOUT=10

Do you want to learn more details about RMAN, then read the following articles.

https://ittutorial.org/rman-backup-restore-and-recovery-tutorials-for-beginners-in-the-oracle-database/