In this post we’re going to talk about Oracle SQL developer “SQL Error 17002 Sqlstate 08006” error on Windows. We’ll talk about the error code and how to fix it fast.
Why Does SQL Error 17002 Sqlstate 08006 Shows Up?
Most of the times it shows up because there is incorrect Misconfiguration or listener isn’t running. Before you’re able to connect with Oracle database, SQL developer must be configured correctly and listener has to be running. The listener handles databases connection, by default the SQL settings does not need listener for connecting to database and so it has to be configured.
SQL Error 17002 Sqlstate 08006
Another possible reason for this SQL error could be database sessions have been terminated by the network firewall or interrupted by another reason. In this case you have to make sure firewall isn’t stopping idle connections.
Connectivity problems between oracle integration and connectivity agent can be the cause of this error also, or when the connectivity agent is disabled. You have to make sure connectivity agent is running. You can check the status under your Dashboards and Agents in oracle integration.
How To Fix SQL Error 17002 Sqlstate 08006
The fixes to this SQL error code is mostly about fixing or configuring the listener. We’ll also share other fixes that will help.
Fix No.1: Ensure listener is running
This can be checked from Windows Service Manager or using Command Prompt. Follow these steps to check the status;
Checking listener status using Windows Service Manager:
- Press Windows + R to open Run Dialogue.
- Type msc in the dialogue box.
- In the list of services, TNS listener is listed, make sure it’s running, the status is shown beside each service. If it’s not running you just need to right-click and click Start.
Checking with command prompt:
Open command prompt, you can do that by typing cmd in windows search, right-click on it and select ‘Run As Administrator’.
- When the command prompt opens, you type this command: C:>lsnrctl status
- If it’s not running, error will be mentioned multiple times, and you need to start it.
- To start the listener service, you need to type this command: C:>lsnrctl start
lsnrctl status
Fix No.2: Making sure the listener has the right configurations
- Open Oracle SQL Developer.
- Right click on database name and select properties.
- A window will open and you need to take note of the Hostname and port values under the ‘details’ tab.
- The default port is 1521, but sometimes it can be 1522, it has to be changed.
- Now back to checking hostname, you should type C:>hostname.
- The hostname will immediately appear below this command and if you’re receiving the SQL error code 17002, in most cases it will be different from the hostname that appeared when you right-click on the database name in the previous step. Remember that I told you to take note of the Hostname, this difference occurs when the computer name is changed. In this situation, the hostname has to be corrected in the connection Window, and the port value also should be changed to 1521 if that’s not the value.
- The next step now is to open tnsnames.ora file and check to confirm that the hostname and port is correct. The full path is; %ORACLE_HOME%/network/admin/tnsnames.ora. if not you need to change the values appropriately.
- Open the Windows Service Manager and Restart OracleserviceXE by right clicking and then click restart.
- Now you should test the connection to see if things are ok. When you’re sure all values are correct, that’s the Port, Hostname, username and password, you should click the test button. If connection show successful it means the problem has been rectified.
- After that you can now click connect and can now browse and query your database.
This fix can be lengthy or seem complex to most users but that’s the way to go about it.
Fix No.3: Restart Oracle TNS listener
As we’ve mentioned in the first fix, you should check whether listener is running or not, so in this case even if it’s running you should restart it. You should follow the same procedure in the first fix. Restarting the listener has work for some, you should give it a try.
Conclusion
So far these are some of the best fixes to SQL Error 17002 Sqlstate 08006, the problem most of the time has to do with listener and you need to ensure that it’s pointing to the correct port and server. Once you can figure this out, you’ll definitely get rid of the problem. Do let us know in the comments if these fixes have solved the SQL error for you, if you also have more ideas to share please drop your comments below for our readers.
I get the above error when connecting to a new schema.
Note that when my VPN is connected initially all the connections(C1,C2,C3…) work fine. I then start working on one connection(C1) and after say 2 hours if i try to connect to C2 I have this error.
I have to disconnect and reconnect to the VPN every time, which is very annoying when you have to do it at least 15-20 times in a day.
Any idea why I could have this issue?
asked Jul 3, 2015 at 7:16
It seems that your vpn closes the connection after some time.
Check if you can ping the database ip before trying connect to it.
If you can’t ping it the problem has nothing to do with java, sql, sqldeveloper, and javascript. It is a network problem that you can try to solve with your network administrator.
answered Jul 3, 2015 at 7:19
In my case, the entry from hosts file was the problem.
Un-commented the following line from hosts worked for me.
# 127.0.0.1 localhost
answered Jul 9, 2019 at 6:44
One reason could be the services OracleServiceORCL and OracleOra…Listener have been off, Check the service running on your computer and turn this two services on, then the problem might be solved.
To avoid this from happening again, try to change the property of the service to automatically run.
answered Feb 14, 2020 at 11:34
0
I have an Oracle database 12c standard edition release 12.2.0.1.0 running on a Linux instance of AWS ec2. When I try to connect to it remotely from my machine (macOS) using SQL Developer I get an IO Error: The Network Adapter could not establish the connection Vendor Code 17002 error.
- connecting using sqlplus from my machine:
sqlplus cd2/ @ec2-publicIp.myCloud.compute.amazonaws.com:1522/orcl
SQL*Plus: Release 19.0.0.0.0 - Production on Mon Aug 3 15:30:56 2020
Version 19.3.0.0.0
Copyright (c) 1982, 2019, Oracle. All rights reserved.
ERROR:
ORA-12541: TNS:no listener
- On the ec2 instance, Security Groups, a TCP 1522 port is open for my machine’s public IP
- telnet to the instance, port 1522 seems to indicate that the port is open:
telnet ec2-pubIp.compute.amazonaws.com 1522
Trying pubIp...
telnet: connect to address pubIp: Connection refused
telnet: Unable to connect to remote host
- Port 1522 is used consistently across all the configurations
- I verified that the ec2 hostname (
hostnamecommand) matches the service name output fromlsnrctl status. The output showslocalhostinstead ofip-localIp.myCloud.compute.internal.
$ hostname
ip-localIp.myCloud.compute.internal
$ lsnrctl status
LSNRCTL for Linux: Version 12.2.0.1.0 - Production on 03-AUG-2020 15:20:44
Copyright (c) 1991, 2016, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=ip-localIp.myCloud.compute.internal)(PORT=1522)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 12.2.0.1.0 - Production
Start Date 03-AUG-2020 13:30:22
Uptime 0 days 1 hr. 50 min. 22 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/centos/product/12.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /u01/app/centos/diag/tnslsnr/ip-localIp/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=localhost)(PORT=1522)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1522)))
Services Summary...
Service "orcl.myCloud.compute.internal" has 1 instance(s).
Instance "orcl", status READY, has 1 handler(s) for this service...
Service "orclXDB.myCloud.compute.internal" has 1 instance(s).
Instance "orcl", status READY, has 1 handler(s) for this service...
The command completed successfully
- The hostname and port also matches the default listener configured in
listener.ora:
cat /u01/app/centos/product/12.2.0/dbhome_1/network/admin/listener.ora
# listener.ora Network Configuration File: /u01/app/centos/product/12.2.0/dbhome_1/network/admin/listener.ora
# Generated by Oracle configuration tools.
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = ip-localIp.myCloud.compute.internal)(PORT = 1522))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1522))
)
)
- Oracle parameters are as shown, again both host and port match:
SQL> show parameter listener_networks
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
listener_networks string
SQL> show parameter local_listener
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
local_listener string (ADDRESS=(PROTOCOL=TCP)(HOST =
ip-localIp.myCloud
.compute.internal)(PORT = 1522
))
SQL> show parameter remote_listener
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
remote_listener string
- I can connect from the ec2 instance:
sqlplus / as sysdba - I can connect from the ec2 instance as a schema/user cd2:
sqlplus cd2/ @orcl
SQL*Plus: Release 12.2.0.1.0 Production on Mon Aug 3 18:04:13 2020
Copyright (c) 1982, 2016, Oracle. All rights reserved.
Enter password:
Last Successful login time: Mon Aug 03 2020 18:03:52 +00:00
Connected to:
Oracle Database 12c Standard Edition Release 12.2.0.1.0 - 64bit Production
SP2-0310: unable to open file "orcl.sql"
SQL> select 1 from dual;
1
----------
1
SQL>
- SQL Developer connection matches both the port and ec2’s public domain name:
- This database server is our dev instance so no license was installed
- Updated
listener.oraby setting theHOSTvalue to0.0.0.0, restarted withlsnrctlbut the result was the same:
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 0.0.0.0)(PORT = 1522))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1522))
)
)
/etc/hostscontent:
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ip-localIp.myCloud.compute.internal
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
- I also tested it with all inbound traffic and all ports opened for the ec2 instance
Most probably you have listener configured wrongly, the hostname you specify in connection string must be the same as in the listener.
First check the Firewall and network related issues.
Check if Oracle Listener service is available and running. If not you may use Oracle Net Configuration Assistant tool to add and register new listener.
If the above steps are ok then you need to configure Oracle Listener appropriately. You may use Oracle Net Manager tool or edit “%ORACLE_HOME%networkadminlistener.ora” file manually.
There are 2 options that need to be considered carefully:
Listening Locations associated with the Listener – Hostname(IP) and Port in Listening Location must exactly match the ones used in the connection string.
For example, if you use 192.168.74.139 as target hostname, then there must be Listening Location registered with the same IP address.
Also make sure the you use the same SID as indicated in Database Service associated with the Listener.
Most probably you have listener configured wrongly, the hostname you specify in connection string must be the same as in the listener.
First check the Firewall and network related issues.
Check if Oracle Listener service is available and running. If not you may use Oracle Net Configuration Assistant tool to add and register new listener.
If the above steps are ok then you need to configure Oracle Listener appropriately. You may use Oracle Net Manager tool or edit “%ORACLE_HOME%networkadminlistener.ora” file manually.
There are 2 options that need to be considered carefully:
Listening Locations associated with the Listener – Hostname(IP) and Port in Listening Location must exactly match the ones used in the connection string.
For example, if you use 192.168.74.139 as target hostname, then there must be Listening Location registered with the same IP address.
Also make sure the you use the same SID as indicated in Database Service associated with the Listener.
May 6, 2021
I got ” ORA-17002: io exception: the network adaptor could not establish the connection Vendor code 17002″ error in Oracle database.
ORA-17002: io exception: the network adaptor could not establish the connection Vendor code 17002
Details of error are as follows.
ORA-17002: io exception: the network adaptor could not establish the connection Vendor code 17002
io exception: the network adaptor could not establish the connection Vendor code 17002
This ORA-17002 error is related with the ORA-12541: TNS:no listener error.
This error is related with the listener of database server, if you got this error, then check your database listener as follows.
$ lsnrctl status listener
Listener should be always started.
You can stop and start the Listener as follows.
$ srvctl start listener $ srvctl stop listener
or
$ lsnrctl stop listener $ lsnrctl start listener
Edit the server side sqlnet.ora file and add this parameter:
SQLNET.INBOUND_CONNECT_TIMEOUT=240
There is no need to restart either the listener or the database after this change unless the database is running in shared server mode.
The next dedicated server process that gets spawned will pick up the new setting.
Do you want to learn Oracle Database for Beginners, then read the following articles.
Oracle Tutorial | Oracle Database Tutorials for Beginners ( Junior Oracle DBA )
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Hey guys! Have you ever faced the TNS IO error saying “The network adapter could not establish the connection”? when you are trying to make a new connection in SQL Developer or logging on to the database using SQL*Plus editor. If yes then you are at the right place because here in this blog I am going to show you how you can solve this error.
So without further ado let’s proceed to solve this badass TNS error.
Step 1: Make sure your entries are correct
First of all to solve “The network adapter could not establish the connection” error, check whether you have entered the correct username and password as well as the correct Hostname and Port number. Though these are small things we cannot avoid them. After all “It’s the small things in a relationship that means the most.”
[bctt tweet=”How to solve “The network adapter could not establish the connection” error in just 2 steps” username=”RebellionRider”]
For the valid hostname and port number, you can check the Listener.ora if you have access to your server as the listener is a server process. In case you don’t have access to listener.ora file then you can check the tnsnames.ora file.
In case of Listener.ora file check for Host and Port entry in Listener tag for valid hostname and port number.
Listener.ora
And if you are using TNSnames.ora file for validating the hostname and port number then search for the entry which has the same name as your SID and then check for host and port number entry in that particular tag.
TNSnames.ora
Now try connecting. If this solves your problem then you can avoid the next step. But if “The network adapter could not establish the connection” error is still there, then don’t worry just follow the next step.
Step 2: Is your listener taking a rest?
If your problem is still there and you haven’t gotten rid of that nasty error then there is a possibility that your Listener is not running. To check whether Listener is up and running or not, simply open up your command prompt with Administrative privileges and Write
C:> lsnrctl status
This command will show you the status of your listener. If the output of this command looks like the one shown in the picture below then it clearly means your listener is not running thus next what you have to do is to start the listener.
To start the listener you just have to write
C:> lsnrctl start.
This will start your listener and most probably solve your problem.
Info Byte:
In case you are having problems in starting your listener then try starting “OracleOraDb11g_home1TNSListener” windows service. For that open your Run Command and write services.msc this will open your service panel. Here search for the same and right click to start it.
That’s all you have to do. This must solve the “The network adapter could not establish the connection” error. May the force be with you. Enjoy.
Also, click here to learn how to do initial configuration of Orcale Enterprise Manager to start working with it.
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