**Setup Hostname**

Log into the hostname (ssh)

Run the following command

```
sudo hostnamectl set-hostname NewHostName
```

Also need to update the hosts name

```
sudo vi /etc/hosts
```

***Example of old host file***

```
127.0.0.1       localhost
127.0.1.1       old-hostname.vocus.co.nz old-hostname

# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
```

***Example of updated host***

```
127.0.0.1       localhost
127.0.1.1       New-hostname.vocus.co.nz New-hostname

# The following lines are desirable for IPv6 capable hosts
::1     localhost ip6-localhost ip6-loopback
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

```

While hostnamectl typically applies the changes immediately, some services or applications might still be referencing the old hostname. You can restart network services or reboot the system for a complete refresh, although often it's not strictly necessary.
To restart network services:

```
sudo systemctl restart network-online.target
```

or just reboot

```
Sudo Reboot
```