My setup is as follows:
- Windows 10 Pro with one real (integrated) NIC enabled. The latest available Bonjour for Windows is installed
- Two virtual machines running Linux
- One other Windows laptop on the network
Let's call the Linux VMs A and B, and the two Windows devices X and Y. X is the VM host.
A can ping and connect to B, B can ping and connect to A.
X cannot connect to A or B, neither A or B can ping or connect to X. Y can connect to A and B and vice-versa.
This is not a firewall issue as nothing changes when the Windows Firewall is completely disabled on X.