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Resolving ORA-12203 and TNS-12560 errors

Recently, we have been receiving ORA-12203 and TNS-12560 errors. Any client currently connected, continues to work just fine; but no new connections are allowed. If I stop the OracleTNSListener80 service and restart it, clients can connect again. This lasts for a while and then we get the errors again. It seems that maybe client connections aren't being properly closed and we are running into a maximum number of processes or something. The RDBMS is 8.0.5 on NT 4.0 and most client connections are using SQL*Net v2 using Windows 98 or XP. A couple of things to note is that around the time this problem started, we have been increasing our number of Windows XP clients. We also had a virus on our network servers. Any ideas of the cause? If it was a virus problem, do you think the SQL*Net could be reinstalled? Do you think it is a problem with SQL*Net on the server side or client side?

It is odd that your ORA-12203 and TNS-12560 errors are resolved by bouncing the listener. It could be your virus that is causing the problem. Connections to/from Windows platforms require the use of Microsoft's TCP/IP stack and this could be corrupt. I suggest making sure that your server (and workstations) are virus free. After that, you can try to reinstall SQL*Net.

Another problem is that you are using SQL*Net V2 on Win 98 and XP. You should be using Net8 instead. This may be contributing to your problems. I suggest upgrading your clients to Net8.

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