Listener Hangs - TNS-01181: Internal registration connection limit reached (Doc ID 549649.1)

Last updated on MARCH 31, 2022

Applies to:

Symptoms

Suddenly the listener starts hanging and any connection attempt via the listener also hangs. The listener needs to be restarted for normal operations but again the listener starts hanging after some time.  A connection attempt from the rogue client or application giving the listener invalid connect data as shown in  the excerpt taken from the listener log OR the listener thinks that the client application is sending bad connect data.

Adding the following parameter in the listener.ora and setting it to a high value might delay the inevitable listener hang but cannot prevent the listener from hanging.

For Example:
------------
In Listener.ora :

MAX_REG_CONNECTIONS_<listener>=1000

Cause

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