основная помощь для конфигурации NAT необходима

I haven't tested this, but this is what I would try.

1. Create a new bridge on the host with brctl

   brctl addbr br0
   

2. Configure the VM with bridged networking connected to this bridge

3. Assign a private subnet to the bridge and give the host an IP on it

   ip addr add 192.168.1.1/24 dev br0
   ip route add 192.168.1.0/24 dev br0
   

4. Either statically configure the VM with an IP on this range (e.g. 192.168.1.2), or setup a DHCP server on the host (e.g. dnsmasq or VirtualBox's dhcpserver).

5. Check that the host can access the VM and vice versa on the private IPs

6. Attach the static IP to eth0 on the host

   ip addr add 1.0.2.30/24 dev eth0
   

7. Check that you can connect to the host on the additional IP from outside

8. Enable IP forwarding on the host

   echo 1 > /proc/sys/net/ipv4/ip_forward
   

9. Configure iptables to SNAT outgoing packets from the VM

   iptables --table nat --append POSTROUTING --source 192.168.1.0/24 --jump SNAT --to 1.0.2.30
   iptables --append FORWARD --source 192.168.1.0/24 --jump ACCEPT
   

10. Check that the VM has connectivity to the Internet

11. Configure iptables to DNAT packets to the additional IP to the VM

    iptables --table nat --append PREROUTING --destination 1.0.2.30 --to-destination 192.168.1.2
    iptables --append FORWARD --destination 192.168.1.2 --jump ACCEPT
    

12. Убедитесь, что вы можете подключиться к виртуальной машине по дополнительному IP извне.