Basic Client Hyper-V test lab connectivity issue.

Hi Experts

I've built a small test lab using Client Hyper-V on my Windows 10 machine at home.  It is in its infancy at the moment, as I am learning as I go.  See attached diagram for an overview

I have set up a server and a client and given them both static IP addresses.  I want to keep the servers away from the clients so I have set up a VyOS software router inbetween my two virtual switches.  As far as I can tell I have set the router up correctly and i can ping the nearside interfaces from the server machine and also the client machine.  However, when I try to ping the client machine from the server I get a Request Timed Out message.

I have disabled the firewall on both VMs and still get the same RTO message.   I don't believe the firewall is set on the VyOS by default but I may be wrong ?

So what could be blocking the ping request getting back, if I am right the RTO means the ping request is reaching its destination but for some reason not getting back to the sender ??

I have not installed anything else such as AD DS, DHCP, DNS, anti-virus etc on either the server or the client as yet.

As I say I may be overlooking something fuundamental at this stage but I'm only just getting started with this and wanted to get it right.

Any help would be great

Thanks
Matthew
testlab.jpg