Finding out networking names

Each machine on a network has a unique name. Generally, each user within a site also has a unique user name. You should know the name of your own machine and the name of any machine with which you want to communicate over the network. Also you should know the user name of any person to whom you want to send mail. Because you might not remember these various names, several simple network commands can provide this information.

You can find out the name of your own machine using the hostname(TC) command without any arguments. (A machine on the network is sometimes called a host.) The response is the name by which your machine is known on the network.

To see a list of the names of other machines on your network, use the ruptime command. (The ``r'' in the command name stands for remote. Remote refers to a machine across the network; your own machine is known as the local machine.) The output from the ruptime command shows the amount of time each machine has been up on the network:

seattle     up 26 days, 15:00, 1 user, load average: 2.08, 2.01, 2.00
berlin      down         4:07
sydney      up 43 days  01:27, 4 users, load average: 3.00, 3.00, 3.00

You may also be able to view a list of machine names stored in the file /etc/hosts. This file contains a listing of machine names and their Internet (IP) addresses.

To find out a person's user name, use the finger command and give the person's first or last name. For example, for a person named Rebecca Simpson, you might enter:

finger simpson

The response might be something like this:

Login name: rsimpson                 	In real life: Rebecca Simpson
Directory: /u/rsimpson               	Shell: /bin/sh
No Plan.