A loopback test is a connection from the database server back to itself. Many network protocols provide a means of testing network connections. The utility PING can be used for TCP/IP network. In a TCP/IP network, each computer has a unique IP address. A name resolution service, such as Domain Name System (DNS), can be used to map the IP address of a computer with its host name. If a name resolution service is not used, then the mapping is typically stored in a centrally maintained file called hosts. This file is located in the /etc directory on UNIX and the.
