How to resolve “TNS-12547: TNS:lost contact TNS-12560: TNS:protocol adapter error TNS-00517: Lost contact” | Karan Rajpoot

In this article you will get to know How to resolve “TNS-12547: TNS:lost contact TNS-12560: TNS:protocol adapter error TNS-00517: Lost contact”

Error: – “TNS-12547: TNS: lost contact TNS-12560: TNS: protocol adapter error TNS-00517: Lost contact”

Cause: – This error occurs when loopback entries have been missed in the /etc/hosts file.

Solution: – To resolve this error you need to put the loopback entries in the /etc/hosts file.

Example: – 

[[email protected] bin]$ lsnrctl start

 

LSNRCTL for Linux: Version 11.2.0.4.0 – Production on 14-APR-2019 22:08:16

 

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

 

Starting /u02/app/oracle/product/11.2.0/db_1/bin/tnslsnr: please wait…

 

TNSLSNR for Linux: Version 11.2.0.4.0 – Production

System parameter file is /u02/app/oracle/product/11.2.0/db_1/network/admin/listener.ora

Log messages written to /u02/app/oracle/diag/tnslsnr/prod/listener/alert/log.xml

Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=prod.radical.com)(PORT=1521)))

 

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=prod.radical.com)(PORT=1521)))

TNS-12547: TNS: lost contact

 TNS-12560: TNS: protocol adapter error

  TNS-00517: Lost contact

   Linux Error: 104: Connection reset by peer

 

Note: – To resolve the issue need to put the below loopback entries in the /etc/hosts file.

127.0.0.1    prod.localdomain prod localhost4.localdomain4

::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

 

 

After making the changes, Now you can restart your listener.

 

[[email protected] ~]$ lsnrctl start

 

LSNRCTL for Linux: Version 11.2.0.4.0 – Production on 14-APR-2019 22:11:05

 

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

 

Starting /u02/app/oracle/product/11.2.0/db_1/bin/tnslsnr: please wait…

 

TNSLSNR for Linux: Version 11.2.0.4.0 – Production

System parameter file is /u02/app/oracle/product/11.2.0/db_1/network/admin/listener.ora

Log messages written to /u02/app/oracle/diag/tnslsnr/prod/listener/alert/log.xml

Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=prod.radical.com)(PORT=1521)))

 

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=prod.radical.com)(PORT=1521)))

STATUS of the LISTENER

————————

Alias                     LISTENER

Version                   TNSLSNR for Linux: Version 11.2.0.4.0 – Production

Start Date                14-APR-2019 22:11:05

Uptime                    0 days 0 hr. 0 min. 0 sec

Trace Level               off

Security                  ON: Local OS Authentication

SNMP                      OFF

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Listener Parameter File   /u02/app/oracle/product/11.2.0/db_1/network/admin/listener.ora

Listener Log File         /u02/app/oracle/diag/tnslsnr/prod/listener/alert/log.xml

Listening Endpoints Summary…

  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=prod.radical.com)(PORT=1521)))

Services Summary…

Service “dr” has 1 instance(s).

  Instance “dr”, status UNKNOWN, has 1 handler(s) for this service…

Service “prod” has 1 instance(s).

  Instance “prod”, status UNKNOWN, has 1 handler(s) for this service…

The command completed successfully

 

 

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