Static IP Config
Setting a static IP is useful to ensure that any DHCP activity on your network won't change the location of your RPi.
To do this we need to edit
sudo nano /etc/network/interfaces
replace the line
iface eth0 inet dhcp with
iface eth0 inet static address 192.168.0.20 netmask 255.255.255.0 gateway 192.168.0.1
Exit and save the file with CTRL-X followed by Y to confirm the changes.
The gateway is the address for the router and may need to be adjusted.