Appropriate network communication software must be installed and running before you run the database server. If you are running reliable network software with just one network installed, this should be straightforward. If you experience problems, if you are running non-standard software, or if you are running multiple networks, read the discussion of network communication issues in the Installation and Configuration Guide. You should also refer to the documentation of your network vendor.
You should confirm that other software that requires network communications is working properly before running the database server.
For example, if you are running under the TCP/IP protocol, you may want to confirm that ping and telnet are working properly. The ping and telnet applications are provided with many TCP/IP protocol stacks.
