Oracle client ORA-12541: TNS:no listener

You need to set oracle to listen on all ip addresses (by default, it listens only to localhost connections.)

Step 1 – Edit listener.ora

This file is located in:

  • Windows: %ORACLE_HOME%\network\admin\listener.ora.
  • Linux: $ORACLE_HOME/network/admin/listener.ora

Replace localhost with 0.0.0.0

# ...

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
      (ADDRESS = (PROTOCOL = TCP)(HOST = 0.0.0.0)(PORT = 1521))
    )
  )

# ...

Step 2 – Restart Oracle services

  • Windows: WinKey + rservices.msc
  • Linux (CentOs):sudo systemctl restart oracle-xe

Leave a Comment