"The Network Adapter could not establish the connection" While Connecting From SQL Developer using SCAN (Doc ID 2138671.1)

Last updated on MAY 25, 2016

Applies to:

Oracle SQL Developer - Version 3.0 to 4.1 [Release 3 to 4]
Information in this document applies to any platform.

Symptoms

JDBC connection to database from SQL*Developer 3.x works at times, but fails most times with the following error:

IO Exception: The Network Adapter could not establish the connection

Changes

 None.

Cause

Sign In with your My Oracle Support account

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

My Oracle Support provides customers with access to over a
Million Knowledge Articles and hundreds of Community platforms