Silly,
What device are you trying to get the IP address for? If it is a PC with windows, you can use this route – Start – Run (enter in CMD) a box will pop up – type “ipconfig” then enter. The IP address of the computer and a few other IP addresses used will pop up.
On a PC this IP address can change everytime you start it up.
Is this what you need? If not let us know what device you are referring to.
Jason