Unable to connect 3 vm together

[p730]

Hi,
I'm trying to connect 3 virtual machines together, all are ubuntu 18.04, and I'm having trouble ssh and pinging each of the machines.
the 3 machines are
Routers:
network1 : 192.168.100.1 , net2 : 192.168.101.1
client:
192.168.100.2
Server:
192.168.101.2
all 3 virtual machines are configured using internal network

when I try pinging the client from router this is what I got:

ping.PNG

and ssh :
ssh.jpg

I configured the network interface using netplan like this :
netplan.jpg

network on client machine:
netplanClient.PNG

I know lots of people are asking this questions but I've tried all of them and It still doesn't work for me.
I also tried allowing firewall for port 80 and even disabled it.

I'm not sure how to connect these 3 vm togethers.
any help would be appreciated!
thank you in advance!

[TheFu]

Which hypervisor?
Using the bridge-utils package with KVM, these NAT connections should work.
For something like virtualbox, probably best to read the networking chapter in that manual. https://www.virtualbox.org/manual/ch06.html Networks aren't connected when they seem to be.

Also, please post text, wrapped in code tags, not images.