Oracle 12c install error - Oracle Net Configuration Assistant keep searching the listener ports - Checking for free port in range: 1521-1540 - Validating end-point: TCP:1521

Oracle 12c install error - Oracle Net Configuration Assistant keep searching the listener ports 

The installer will stuck on the Oracle Net Configuration Assistant and will never complete, it will keep searching the listener ports, starting from 1521, it will keep searching the next port 1522, then so on. 

Even the listener port 1521 is free and not being used, but Net Configuration Assistant keep putting the following messages in the directory "cfgtoollogs/netca"

[main] [ 2022-03-06 13:36:59.285 NZDT ] [ConfigureListener.isHASConfigured:1648]  Is Oracle Restart configured: false

[main] [ 2022-03-06 13:36:59.285 NZDT ] [ConfigureListener.isHASRunning:1677]  Is Oracle Restart running: false

[main] [ 2022-03-06 13:36:59.285 NZDT ] [ConfigureListener.listenerExists:411]  Is listener "LISTENER" already exists: false

[main] [ 2022-03-06 13:36:59.285 NZDT ] [ConfigureListener.typicalConfigure:272]  Checking for free port in range: 1521-1540

[main] [ 2022-03-06 13:36:59.285 NZDT ] [ConfigureListener.validateEndPoint:1074]  Validating end-point: TCP:1521

oracle.net.ca.IllegalEndpointException: The information provided for this listener is currently in use by other software on this computer.

        at oracle.net.ca.ConfigureListener.validateEndPoint(ConfigureListener.java:1102)

        at oracle.net.ca.ConfigureListener.typicalConfigure(ConfigureListener.java:279)

        at oracle.net.ca.SilentConfigure.performSilentConfigure(SilentConfigure.java:212)

        at oracle.net.ca.InitialSetup.<init>(NetCA.java:4353)

        at oracle.net.ca.NetCA.main(NetCA.java:452)

[main] [ 2022-03-06 13:39:15.023 NZDT ] [ConfigureListener.typicalConfigure:283]  The information provided for this listener is currently in use by other software on this computer.

[main] [ 2022-03-06 13:39:15.023 NZDT ] [ConfigureListener.validateEndPoint:1074]  Validating end-point: TCP:1522

oracle.net.ca.IllegalEndpointException: The information provided for this listener is currently in use by other software on this computer.

        at oracle.net.ca.ConfigureListener.validateEndPoint(ConfigureListener.java:1102)

        at oracle.net.ca.ConfigureListener.typicalConfigure(ConfigureListener.java:279)

        at oracle.net.ca.SilentConfigure.performSilentConfigure(SilentConfigure.java:212)

        at oracle.net.ca.InitialSetup.<init>(NetCA.java:4353)

        at oracle.net.ca.NetCA.main(NetCA.java:452)

[main] [ 2022-03-06 13:41:30.083 NZDT ] [ConfigureListener.typicalConfigure:283]  The information provided for this listener is currently in use by other software on this computer.

[main] [ 2022-03-06 13:41:30.083 NZDT ] [ConfigureListener.validateEndPoint:1074]  Validating end-point: TCP:1523

oracle.net.ca.IllegalEndpointException: The information provided for this listener is currently in use by other software on this computer.

        at oracle.net.ca.ConfigureListener.validateEndPoint(ConfigureListener.java:1102)

        at oracle.net.ca.ConfigureListener.typicalConfigure(ConfigureListener.java:279)

        at oracle.net.ca.SilentConfigure.performSilentConfigure(SilentConfigure.java:212)

        at oracle.net.ca.InitialSetup.<init>(NetCA.java:4353)

        at oracle.net.ca.NetCA.main(NetCA.java:452)

[main] [ 2022-03-06 13:43:45.041 NZDT ] [ConfigureListener.typicalConfigure:283]  The information provided for this listener is currently in use by other software on this computer.

[main] [ 2022-03-06 13:43:45.041 NZDT ] [ConfigureListener.validateEndPoint:1074]  Validating end-point: TCP:1524

oracle.net.ca.IllegalEndpointException: The information provided for this listener is currently in use by other software on this computer.

        at oracle.net.ca.ConfigureListener.validateEndPoint(ConfigureListener.java:1102)

        at oracle.net.ca.ConfigureListener.typicalConfigure(ConfigureListener.java:279)

        at oracle.net.ca.SilentConfigure.performSilentConfigure(SilentConfigure.java:212)

        at oracle.net.ca.InitialSetup.<init>(NetCA.java:4353)

        at oracle.net.ca.NetCA.main(NetCA.java:452)

[main] [ 2022-03-06 13:46:00.082 NZDT ] [ConfigureListener.typicalConfigure:283]  The information provided for this listener is currently in use by other software on this computer.

[main] [ 2022-03-06 13:46:00.083 NZDT ] [ConfigureListener.validateEndPoint:1074]  Validating end-point: TCP:1525

oracle.net.ca.IllegalEndpointException: The information provided for this listener is currently in use by other software on this computer.

        at oracle.net.ca.ConfigureListener.validateEndPoint(ConfigureListener.java:1102)

        at oracle.net.ca.ConfigureListener.typicalConfigure(ConfigureListener.java:279)

        at oracle.net.ca.SilentConfigure.performSilentConfigure(SilentConfigure.java:212)

        at oracle.net.ca.InitialSetup.<init>(NetCA.java:4353)

        at oracle.net.ca.NetCA.main(NetCA.java:452)

[main] [ 2022-03-06 13:48:17.004 NZDT ] [ConfigureListener.typicalConfigure:283]  The information provided for this listener is currently in use by other software on this computer.

[main] [ 2022-03-06 13:48:17.005 NZDT ] [ConfigureListener.validateEndPoint:1074]  Validating end-point: TCP:1526

oracle.net.ca.IllegalEndpointException: The information provided for this listener is currently in use by other software on this computer.

        at oracle.net.ca.ConfigureListener.validateEndPoint(ConfigureListener.java:1102)

        at oracle.net.ca.ConfigureListener.typicalConfigure(ConfigureListener.java:279)

        at oracle.net.ca.SilentConfigure.performSilentConfigure(SilentConfigure.java:212)

Resolution:

- check the /etc/hosts file, it should contain the fully qualified name of the host machine with the IP.

- update the /etc/hosts with the correct hostname / ip and Oracle Net Configuration Assistant will pick the right hostname and will get the listener port for the configuration.

- to make sure check the installer screen , also log file can be checked under "cfgtoollogs/netca"

[main] [ 2022-03-06 13:59:35.198 NZDT ] [ConfigureListener.typicalConfigure:283]  The information provided for this listener is currently in use by other software on this computer.

[main] [ 2022-03-06 13:59:35.198 NZDT ] [ConfigureListener.validateEndPoint:1074]  Validating end-point: TCP:1531

[main] [ 2022-03-06 14:00:50.125 NZDT ] [ConfigureListener.isPortFree:1155]  Checking if port 1531 is free on local machine...

[main] [ 2022-03-06 14:00:50.126 NZDT ] [ConfigureListener.isPortFree:1170]  InetAddress.getByName(127.0.0.1): /127.0.0.1

[main] [ 2022-03-06 14:00:50.126 NZDT ] [ConfigureListener.isPortFree:1172]  Local host IP address: oracle12cdb.testlab.com/192.168.1.100

[main] [ 2022-03-06 14:00:50.127 NZDT ] [ConfigureListener.isPortFree:1174]  Local host name: oracle12cdb.testlab.com

[main] [ 2022-03-06 14:00:50.127 NZDT ] [ConfigureListener.isPortFree:1207]  IP Address: oracle12cdb.testlab.com/192.168.1.100, Is IPv6 Address: false

[main] [ 2022-03-06 14:00:50.127 NZDT ] [ConfigureListener.isPortFree:1210]  IP Address: oracle12cdb.testlab.com/192.168.1.100, Is Link-Local Address: false

[main] [ 2022-03-06 14:00:50.127 NZDT ] [ConfigureListener.isPortFree:1235]  Creating ServerSocket on Port:1531, IP Address: oracle12cdb.testlab.com/192.168.1.100

[main] [ 2022-03-06 14:00:50.130 NZDT ] [ConfigureListener.isPortFree:1238]  Created ServerSocket successfully.

[main] [ 2022-03-06 14:00:50.130 NZDT ] [ConfigureListener.isPortFree:1250]  Creating ServerSocket on Port:1531, Local IP Address: /127.0.0.1

[main] [ 2022-03-06 14:00:50.131 NZDT ] [ConfigureListener.isPortFree:1254]  Created ServerSocket successfully.

[main] [ 2022-03-06 14:00:50.131 NZDT ] [ConfigureListener.isPortFree:1260]  Creating ServerSocket on Port:1531

[main] [ 2022-03-06 14:00:50.131 NZDT ] [ConfigureListener.isPortFree:1263]  Created ServerSocket successfully.

[main] [ 2022-03-06 14:00:50.131 NZDT ] [ConfigureListener.isPortFree:1283]  Returning is Port 1531 free: true

[main] [ 2022-03-06 14:00:50.131 NZDT ] [ConfigureListener.validateEndPoint:1129]  Validation...Complete for TCP/TCPS.

[main] [ 2022-03-06 14:00:50.131 NZDT ] [ConfigureListener.typicalConfigure:289]  Using port: 1531

[main] [ 2022-03-06 14:00:50.136 NZDT ] [ConfigureListener.isPortFree:1155]  Checking if port 1531 is free on local machine...

[main] [ 2022-03-06 14:00:50.136 NZDT ] [ConfigureListener.isPortFree:1170]  InetAddress.getByName(127.0.0.1): /127.0.0.1

[main] [ 2022-03-06 14:00:50.136 NZDT ] [ConfigureListener.isPortFree:1172]  Local host IP address: oracle12cdb.testlab.com/192.168.1.100

[main] [ 2022-03-06 14:00:50.136 NZDT ] [ConfigureListener.isPortFree:1174]  Local host name: oracle12cdb.testlab.com

[main] [ 2022-03-06 14:00:50.136 NZDT ] [ConfigureListener.isPortFree:1207]  IP Address: oracle12cdb.testlab.com/192.168.1.100, Is IPv6 Address: false

[main] [ 2022-03-06 14:00:50.136 NZDT ] [ConfigureListener.isPortFree:1210]  IP Address: oracle12cdb.testlab.com/192.168.1.100, Is Link-Local Address: false

[main] [ 2022-03-06 14:00:50.136 NZDT ] [ConfigureListener.isPortFree:1235]  Creating ServerSocket on Port:1531, IP Address: oracle12cdb.testlab.com/192.168.1.100

[main] [ 2022-03-06 14:00:50.136 NZDT ] [ConfigureListener.isPortFree:1238]  Created ServerSocket successfully.

[main] [ 2022-03-06 14:00:50.136 NZDT ] [ConfigureListener.isPortFree:1250]  Creating ServerSocket on Port:1531, Local IP Address: /127.0.0.1

[main] [ 2022-03-06 14:00:50.137 NZDT ] [ConfigureListener.isPortFree:1254]  Created ServerSocket successfully.

[main] [ 2022-03-06 14:00:50.137 NZDT ] [ConfigureListener.isPortFree:1260]  Creating ServerSocket on Port:1531

[main] [ 2022-03-06 14:00:50.137 NZDT ] [ConfigureListener.isPortFree:1263]  Created ServerSocket successfully.

[main] [ 2022-03-06 14:00:50.137 NZDT ] [ConfigureListener.isPortFree:1283]  Returning is Port 1531 free: true