.netoracleconnectionodp.netora-12541

ODP .NET TNS:no listener


I'm currently trying to connect to an Oracle database. I can connect fine on my development machine, but when I deploy to my Win2k3 sp2 server I get the following error.

Faile to open connection... Oracle.DataAccess.Client.OracleException ORA-12541: TNS:no liestener at Oracle.DataAccess.Client.OracleException.HandleErrorHelper(Int32 errCode, OracleConnection conn, IntPtr opsErrCtx, OpoSqlValCtx* pOpoSqlValCtx, Object scr, String procedure, Boolean bCheck)

Any thoughts, ideas, instructions would be helpful. I'm using Oracle.DataAccess.dll version 4.112.1.2.

Thanks


Solution

  • The actual issue was a firewall.

    Apparently my local development machine had access to the server hosting Oracle, but my development Server did not. Once there was an open connection between the two servers, the TNS:no listener error went away.

    This appears to have been a bogus error message returned by the Oracle Client. The listener was there and my configuration (connection string) was valid, but there was no available connection what-so-ever between the two machines.