No ip to ssh into rpi3 (direct ethernet connection)

[justintan2002]

The wifi via laptop doesn't work as I did not enable the IP forward configuration on my laptop. Instead, I configured the raspi to connect directly to the wifi which only works when the ethernet cable is not connected.

[summers]

That isn't a surprise, you could probably enable forwarding on the laptop, in ubuntu. But as you have wifi, it isn't worth doing. As much as anything setting up forwarding is only the start of a network connection, the packets then need to be routable, which means either doing NAT on the laptop, or setting up routing tables.

Anyway for you set up, you know you want the WAN to go via the wifi. So whats probably best is in the ethernet configuration, don't set either a gateway or dns. This should mean that the wifi gateway and dns take priority.

So that should give you both connection to the laptop, and connection to the internet.

There is an interesting point here, it shows would have to understand your network connectivity, before deciding how to route packets. So see this as a learning experience