Problem statement :
In a normal web based application and where many developers would be working on a single environment having an oracle server in each is not at all suggestible hence the approach would be centralized. Oracle server will be installed in one machine and developer would connect to that server using clients such as sql developer, toad etc., and retrieve data using queries. This post is about problem encountered while trying to connect to oracle server using sql developer from other computer in the same network (i.e., machine where the oracle server is installed and machine from where the accessing is being done are connected via LAN). Now the problem I am facing while connecting to an oracle instance in server is "The Network Adapter could not establish the connection". A Sample screenshot gives a brief picture of the problem which I was facing,
The problem in my case was the firewall. The Firewall of server where oracle has installed is stopping my sql developer to connect to the server. Hence there has to be exception added for the firewall to allow this communication. This is done using the following approach.
The approach I have tried giving as depth as possible the steps of which are given below,
Below steps have to be performed in the server where oracle is installed (the overview of the resolution is to add
Step 1 : Open Windows firewall from control panel and locate a link which says "Allow a program or feature through Windows Firewall", this is highlighted in the below picture.
Step 2 : Once you click on that you would see something similar to below. Please click on the "Change settings" and click on "Allow another program".
Step 3 : sql developer would communicate with server using tnslistner which listens if there is any incoming signal to the server. Hence this has to be given as an exception for windows firewall. Locate to the file where tnslistner.exe is available in the server (In my case it was "C:\oraclexe\app\oracle\product\10.2.0\server\BIN"). And select TNSLSNR.exe file from the pop up.
Once you say "Add" this exception will be added to the windows exception list.
Then click on "Ok" from the screen and that's it. This worked in my case. The final response of sql developer while connecting is