How to forward through NAT RRas port to the second NICs?

Question

Windows

There are two hosts with virtual machines. Each host has its own Internet access, with its own ip (A and B). Each host has its own DHCP (77.0 and 78.0 for HyperV virtual machines). Static is registered on each server in the spirit of 192.168.77.0 255.255.255.0 10.10.15.2 LAN10Gb, addresses are changed on the second one. Virtual machines see a neighboring host, see cars on a neighboring host from a different subnet through a separate network adapter, on which a link is directly 10 GB.

Hosts 77 and 78 have their own Nat RRAS. It forwards ports to virtual cars. (For example, we go to Internet A with port 222, we get to the VM with ip 192.168.78.22). The second is similar.

The question is very strange...
It is necessary that the NAT of host 1 forwards the port to the VMs of host 2. For example, we go to the Internet A, host 78, to port 223, we want to get to the VM of host B with ip 192.168.78.23. But he doesn't let me. A line with forwarding appears in the mapping (source, destination, port, etc.), but there is no connection. Although virtual machines are friends with each other by local ip, regardless of the subnet.
Need help.
Sorry for the diagram, I drew on my knee.

Answer 1

Your virtual machines are breaking down on the default gateway which is not specified here (I see the default gateway only for subnets 192.168.77.0/78.0)
. the packet comes from the address 1.1.1.1 comes from the Internet A, connects to the machine on the network 77.0, but when you try to send the packet to the address 1.1.1.1, the machine tries to connect to 1.1.1. via Internet B (since she has a default route through this gateway).
You need to make sure that for machines from 78.0, packets from the RRAS server come to machines 77.0 not with the original Source, but with a spoofed one from the 78.0 subnet, for example.
Unfortunately, I do not remember how this is implemented on RRAS and whether it is possible.