My Oracle Support Banner

Windows 2003: TCP Loopback Connections Fail Intermittently with ORA-12541 TNS: No Listener (Doc ID 1532405.1)

Last updated on MARCH 31, 2022

Applies to:

Oracle Net Services - Version to [Release 10.2 to 11.2]
Information in this document applies to any platform.
The problem documented here is limited to the Windows 2003 SP2 platform. It is not relevant to this kind of problem on any other platform. The problem documented here would NEVER occur on a remote client. It is strictly limited to TCP loopback connections or when the client and database server/listener are on the same PC.


Oracle client connections, where the client resides on the same server as the listener, are intermittently failing with the following error:

ORA-12541  TNS:  No listener

Additionally, the TNSPING command would also yield the same error intermittently and frequently:

TNSPING "(address=(protocol=tcp)(port=1521)(host=<myhost>))"

TNS-12541  TNS:  No listener


An Oracle Net client trace would reveal the following underlying TCP errors:


The Windows registry setting for  TcpTimedWaitDelay defaults to 240 seconds or 4 minutes. 





 There would not necessarily be any changes to this environment. 


To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

In this Document

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.