6.2 Confirming Network Availability

Before using Oracle Net to connect a client computer to a database server, confirm that the client computer can successfully communicate with the database server computer. Evaluating network connectivity can eliminate network-based errors.

The following procedure describes how to confirm network connectivity:

1. Confirm that the database server computer can communicate with itself with a loopback test as follows:

   1. To confirm hardware connectivity, enter the following command at the command line:

      ping ip_address

      In the preceding command, ip_address is the IP address of the database server computer, such as the following:

      ping 192.0.2.203

   2. To confirm the DNS or host name is configured properly, enter the following command at the command line:

      ping host_name

      In the preceding command, host_name is the host name of the server.

   3. To test the TCP/IP setup for the server, enter the following command:

      ping 127.0.0.1
      
      ping6 ::1

      The IP address 127.0.0.1 is the standard IPv4 address for a loopback test. The IP address ::1 (0: 0: 0: 0: 0: 0: 0: 1) is the standard IPv6 address for a loopback test.

2. Verify the client computer can successfully communicate with the database server computer.

   The method for verification varies according to the network protocol. For TCP/IP, you can use PING, FTP or TELNET utilities.

   If the client computer cannot reach the server, then verify that the network cabling and network interface cards are correctly connected. Contact your network administrator to correct these problems.