Connect LAN-device to iMac socket and have internet (through WiFi) on LAN-device

Question

I have an iMac which has internet through WiFi. I also have a VOIP-phone with only a LAN socket (no WiFi adapter availalble).

I would like to connect my VOIP-phone to the LAN outlet on my Imac, and let the VOIP phone use the internet connection in my Imac.

How to make sure in the iMac all the internet requests are only going to the WiFi adapter and how to let the iMac behave as a router or bridge for the VOIP-phone?

Answer 1

On my iMac using Yosemite 10.10.3:

1. Open System Preferences application.
2. Select Sharing.
3. Set the window as shown below.
4. Plug device in to ethernet port.

BTW, the iMac acts like a router.