fix: dnat rule add dst restrictions

  ip link set dev "${VM_NET_TAP}" master dockerbridge

  # Add internet connection to the VM

  IP=$(ip address show dev "${VM_NET_DEV}" | grep inet | awk '/inet / { print $2 }' | cut -f1 -d/)

  iptables -t nat -A POSTROUTING -o "${VM_NET_DEV}" -j MASQUERADE

  iptables -t nat -A PREROUTING -i "${VM_NET_DEV}" -p tcp  -j DNAT --to $VM_NET_IP

  iptables -t nat -A PREROUTING -i "${VM_NET_DEV}" -p udp  -j DNAT --to $VM_NET_IP

  iptables -t nat -A PREROUTING -i "${VM_NET_DEV}" -d "${IP}" -p tcp  -j DNAT --to $VM_NET_IP

  iptables -t nat -A PREROUTING -i "${VM_NET_DEV}" -d "${IP}" -p udp  -j DNAT --to $VM_NET_IP

  if (( KERNEL > 4 )); then

    # Hack for guest VMs complaining about "bad udp checksums in 5 packets"