[all variants] Not able to ssh into VM machines

This is the tutorial I'm following atm to create virtual lab of sort

http://www.brianlinkletter.com/how-t...ate-a-network/

I'm stuck at this step

"Connect to each virtual machine"

If I type into terminal of host OS and try to ssh into VM machines running
I get this error


As you can see, port forwarding settings for PC-1 machine in VM to which I'm trying to connect is

Screenshot from 2017-06-10 15-34-34.jpg


Note: Error stays the same with both "gufw" enabled or disabled on host machine.

I'm not entirely sure what is going wrong or what to look into, can anyone shed some light on this?

New to networking, so be patient with me guys :D

Thank if anyone is willing to spend some time here with silly me

Attached Images

• Screenshot from 2017-06-10 15-34-34.jpg (76.7 KB)