---
title: "ORA-12537: TNS:connection closed – When Nothing Else Works! | Official Pythian®® Blog"
description: "In this post, Matheus Boesing offers a quick tip if you face the ORA-12537: TNS:connection closed error when trying to remotely access an open database."
---

[Blog | Pythian ](https://www.pythian.com/blog)

# [ORA-12537: TNS:connection closed – When Nothing Else Works! | Official Pythian®® Blog](https://www.pythian.com/blog/ora-12537-tnsconnection-closed-when-nothing-else-works)

 Written by [Matheus Boesing](https://www.pythian.com/blog/author/matheus-boesing) | Mar 22, 2021 4:00:00 AM

When you’re sure all the TNS listener (SID_LIST_LISTENER in this case) services and db_domain are fine, but you still face the ORA-12537: TNS:connection closed error when trying to remotely access an [open database](https://pythian.com/open-source-platforms/), what can you do next?

```
[oracle@pythiansrv admin]$ sqlplus sys/******@MYDB as sysdba

SQL*Plus: Release 11.2.0.4.0 Production on Wed Feb 3 17:45:29 2021

Copyright (c) 1982, 2013, Oracle. All rights reserved.

ERROR:
ORA-12537: TNS:connection closed
```

## The SETUID workaround

Here’s a quick tip — if you’ve been an [Oracle DBA](https://pythian.com/oracle-dba-services/) for long enough, you’ll know this workaround solves a variety of issues:

```
[oracle@pythiansrv admin]$ cd $ORACLE_HOME/bin
[oracle@pythiansrv bin]$ ls -lrt oracle
-rwxr-x--x. 1 oracle oinstall 242993632 Dec 18 19:20 oracle
[oracle@pythiansrv bin]$ chmod 6751 oracle
[oracle@pythiansrv bin]$ ls -lrt oracle
-rwsr-s--x. 1 oracle oinstall 242993632 Dec 18 19:20 oracle
```

As you can see, the CHMOD 6751 did it again!

## Conclusion

The reason this happened to me is, somehow, these permissions were wrong in my LOCAL host (the one I was trying to use the SQLPlus* from).

I hope my experience helps you. If you have any questions or anything to add, please leave me a comment.

## Oracle Database Consulting Services

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