A TCP/IP host name used to point to the local machine. localhost is always mapped to the special IP address 127.0.0.1.
The command “telnet localhost” would allow the user to test his or her own telnet server without typing the IP Address on the network (i.e. 122.22.82.22). Initial testing in this fashion is often suggested before going live with a service.
It should be noted, however, that testing a service in this manner may not be the best indicator of how it performs (throughput, latency, etc) over the network, as the “loopback” interface that localhost or 127.0.0.1 runs through is not the same as the ethernet interface that the real service will probably run through – a firewall usually blocks ethernet traffic, but rarely loopback traffic. This can prevent a service from actually functioning on the network. Try using (a) “dummynet” instead; this option is available in at least Linux and FreeBSD, most likely more OSes.
Related
- Localhost Program (unrelated)
TakeDown.NET -> “Localhost”