Set or Change Hostname (via the GUI)

• Open System Preferences
• Select Sharing
  Select the Edit button and enter your desired Local Hostname and click OK
  

Note:  If the Edit button is greyed out, click on the Lock Icon, authenticate with an admin account

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To permanently change the Hostname of your device via the terminal

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Set or Change Hostname (via Terminal) - OS X

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10.6 - 10.10

• Open Terminal by going to Applications, then Utilities, and select Terminal

• The type the following:

sudo hostnamescutil –-sset HostName new_hostname
For example:  sudo hostnamescutil –-sset HostName ECE-MAC

To permanently change the Hostname of your device via the terminal

Set or Change Hostname (via Terminal) - OS X 10.6 - 10.8

• Open Terminal by going to Applications, then Utilities, and select Terminal

• The type the following:

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Note:  It may also be necessary to perform the following commands to solidify the changes

sudo scutil --set ComputerName <hostname>
For example: sudo scutil --set ComputerName ECE-MAC
sudo scutil --set LocalHostName <hostname>
For example: sudo scutil –--set HostNameLocalHostName ECE-MAC