How to Reset Network to Default

To reset Network Configuration to factory setting, here are the steps:

1. Turn off Wifi and unplug network connection;

2. Go to  /Library/Preferences/SystemConfiguration

3. Rename  preferences.plist  to  preferences.plist.bak  (just in case it is needed)

4. Reboot and a new preferences.plist will be created with the network configuration reset to factory default.

How to Change Machine Name

To change the name of the Mac, open Sharing in System Preferences.

Enter or change the name of your choice at the space provide:

Note:
Don’t mix this Machine Name up with Short Name and Full Name.   Machine Name is the name you want to call your Mac and to be shown to others in a network environment.

Short Name and Full Name are the names of the user of the Mac.  These two are used to identify who is the user, and to define and create account information on the Mac.