Toad World® Forums

Getting ORA-12545: TNS: permission denied when not connected to internet


I am using Toad for Oracle version and it’s working great when I have an internet connection. OS is Windows 8, Oracle version However when I am not connected to the internet I get ORA-12545: TNS: permission denied when trying to connect to the local database. I have tried disabling my firewall/antivirus and the issue persists. My TNS names refers to the local computer name not the IP. I can connect to the database through SQL without internet. Any ideas what is preventing the connection through Toad when I have no internet service?



I’m experiencing some delays or other issues when responding via email and I’m not seeing my earlier reply so here it is again.

Try using the loopback IP in your tnsnames.ora file,, instead of the computer name.

Hi Theresa,

In addition to what Michael suggests, you might also have a problem with your listener configuration. You may have your listener configured to use a hostname that needs to be resolved by DNS and that DNS server is not available when you are not on the network. In this case, changing the listener configuration to use localhost or would correct that.

Thanks for the quick responses, I have tried to configure the TNS Names and Listener using and localhost and neither made a difference (I did restart the listener after making those changes.) I’m guessing there is something wrong with my listener configuration, I am just using TCP at the moment, should I add a different protocol?

To rule something out, do you have multiple Oracle clients installed and multiple tnsnames.ora files? If so, verify that you are editing the correct one for the client used by Toad.

Good suggestion, I had moved the extra TNS Names from my Oracle Forms orant folder just to be safe but that didn’t work either. After extensive troubleshooting I discovered it was in fact a firewall issue. I had turned ZoneAlarm off however it appears windows firewall turns itself on if ZoneAlarm is shut down. Now I can connect using the PC name for the listener and TNS Names without internet without issue. Thanks much for the good advice, I’ll keep that in mind if I run into issues in the future.