Troubleshooting connectivity problems with Oracle data sources

The most common problem that you might encounter when you configure the federated server to access Oracle data sources is connectivity.

Symptom

If you are not able to connect to an Oracle data source from a federated server, you might need to update the TCP/IP hosts file.

Cause

This problem can be caused by an out of date TCP/IP hosts file.

Resolving the problem

For each host in the DESCRIPTION section of the tnsnames.ora file, you might need to update the TCP/IP hosts file. Whether you update this file depends on how TCP/IP is configured on your network. Part of the network must translate the remote host name that is specified in the DESCRIPTION section in the tnsnames.ora file to an address.

If your network has a name server that recognizes the host name, you do not need to update the TCP/IP hosts file. If your network does not have a name server that recognizes the host name, you need to add an entry in the TCP/IP hosts file for the remote host.

The location of the TCP/IP hosts file depends on the operating system that is running on the federated server:

On federated servers that run Linux® or UNIX: The hosts file is in the /etc/hosts directory.
On federated servers that run Windows: The hosts file is in the x:\winnt\system32\drivers\etc\hosts directory.