How to forward a white ip address to a virtual machine received through a GRE tunnel?

Question

linux

Good day to all.
There is a server on which there are n ip addresses, let it be server "A". There is a second server, virtual machines are raised on it, let it be server "B". A gre tunnel is forwarded between server A and server B, n IP addresses of server A are wrapped in it. One of the IP addresses of server A is connected to server B, the tun interface is up, it works, the ip address is available and used on server B.
On server B, a network bridge, it is assigned a local ip address, virtual machines are connected to the bridge, the server B bridge is pinged from them. The

question is, how can I forward white IP addresses to virtual machines that are connected through a tunnel from server A to server B? Virtual machines should not be behind NAT, IP addresses should be white and fully accessible from virtual machines.

I ask for help, because my qualifications are not enough.

Answer 1

Virtual machines should not be behind NAT, IP addresses should be white and fully accessible from virtual machines.

What is this requirement based on? NAT 1 in 1 does what you need in a completely transparent manner.

Answer 2

Without NAT most likely in any way. If you are not using NAT, you must provide routing, and you have all addresses physically tied to the server.

Answer 3

It reminds me of my network configuration.
The provider gives one /64 IPv6 subnet. A telephone is connected to the computer by wire, to which one of the addresses is forwarded via VPN.
At the same time, an NDP proxy is running on the computer, which responds to NDP requests over the IP phone. The upstream router makes an NDP request, who owns the phone address, the computer replies that it is, the router sends a packet to the computer, it receives it and routes it to the phone network.
In your case with IPv4 it will be an ARP proxy. In this case, the server will respond to ARP requests as if the address of the virtual machine belongs to it, but in fact receive packets for routing somewhere else, and transfer them to the tunnel.