Type the following command:
root@slingshot:~# gedit /etc/network/interfaces
You will now see an editor with the contents of a file.
Find the line that says "iface eth0 inet static" and change "static" to "dhcp".
Next, comment out the line that says "address 10.10.75.1" by prepending a # in front of it (e.g., # address 10.10.75.1)
Next, comment out the line that says "netmask 255.255.0.0" by prepending a # in front of it (e.g., # netmask 255.255.0.0)
This file should now include:
iface eth0 inet dhcp
# address 10.10.75.1
# netmask 255.255.0.0
Now click on Save to save the file.
Now click on the X in the upper right-hand corner to close the file.