Next: 4.11 What To Do Up: 4.10 Miscellaneous Tasks Previous: 4.10.1 System startup files

## 4.10.2 Setting the hostname

In a networked environment, the hostname is used to uniquely identify a particular machine, while in a standalone environment the hostname just gives the system personality and charm. It's like naming a pet: you can always address to your dog as ``The dog,'' but it's much more interesting to assign the dog a name such as Spot or Woofie.

Setting the system's hostname is a simple matter of using the `hostname` command. If you are on a network, your hostname should be the full hostname of your machine, such as `goober.norelco.com`. If you are not on a network of any kind, you can choose an arbitrary host and domainname, such as `loomer.vpizza.com`, `shoop.nowhere.edu`, or `floof.org`.

When setting the hostname, the hostname must appear in the file `/etc/hosts`, which assigns an IP address to each host. Even if your machine is not on a network, you should include your own hostname in `/etc/hosts`.

For example, if you are not on a TCP/IP network, and your hostname is `floof.org`, simply include the following line in `/etc/hosts`:

`127.0.0.1 floof.org localhost`

This assigns your hostname, `floof.org`, to the loopback address 127.0.0.1 (used if you're not on a network). The `localhost` alias is also assigned to this address.

If you are on a TCP/IP network, however, your real IP address and hostname should appear in `/etc/hosts`. For example, if your hostname is `goober.norelco.com`, and your IP address is 128.253.154.32, add the following line to `/etc/hosts`:

`128.253.154.32 goober.norelco.com`

If your hostname does not appear in `/etc/hosts`, you will not be able to set it.

To set your hostname, simply use the `hostname` command. For example, the command

`# hostname -S goober.norelco.com`

sets the hostname to `goober.norelco.com`. In most cases, the `hostname` command is executed from one of the system startup files, such as `/etc/rc` or `/etc/rc.local`. Edit these two files and change the `hostname` command found there to set your own hostname; upon rebooting the system the hostname will be set to the new value.

Next: 4.11 What To Do Up: 4.10 Miscellaneous Tasks Previous: 4.10.1 System startup files