Setting up Proxmox network with additional white IP hetzner (mikrotik like gw)?

Question

Computer networks

Greetings! Help advice. Hetzner has a server, proxmox is installed, additionally rented additional IP. I want to install mikrotik chr as a gateway for other VMs so that it NATs all traffic. I know that hetzner binds to MAC addresses and what is needed in Proxmox, in the network interface settings for mikrotik, which will look in vmbr0 to change the MAC from the Robot panel for additional IP. I re-read the hetzner-a manuals, but everything is difficult. I'm afraid to drop the server with these settings. Please help with advice.

Configuration now:
--------------------------------------------
source /etc/ network/interfaces.d/*

auto lo
iface lo inet loopback

iface lo inet6 loopback

auto enp5s0
iface enp5s0 inet static
address 157.90.YY.XXX/26 (main ip)
gateway 157.90.YY.NNN
up route add -net 157.90.YY.AAA netmask 255.255.255.BBB gw 157.90.YY.NNN dev enp5s0

iface enp5s0 inet6 static
address 2a01:4f8 :xxx:xxxx::2/64
gateway fexx::x

auto vmbr0
iface vmbr0 inet manual
bridge-ports none
bridge-stp off
bridge-fd 0

Additional IP: 157.90.EEE.DDD


The configuration as I understand it for this scheme with Mikrotik:
-------------------------------------------------- --------------------
auto lo
iface lo inet loopback
iface enp5s0 inet manual

auto vmbr0
iface vmbr0 inet static
address 157.90.YY.XXX/26 (main ip)
gateway 157.90.YY.NNN
bridge-ports enp5s0
bridge-stp off
bridge-fd 0
mask 255.255.255.BBB
up route add -net 157.90.YY.AAA netmask 255.255.255.BBB gw 157.90.YY.NNN dev enp5s0 ,
which was originally registered in the hetzner physical interface)
up ip route add 157.90.EEE.DDD/29 dev vmbr0 (additional IP here)

auto vmbr1 (this is a bridge for the local network vm behind mikrotik)
iface vmbr1 inet manual
bridge-ports none
bridge-stp off
bridge-fd 0

-------------------------------------- ------------------------
Please point in the right direction. Poke your nose where you made a mistake or how right.

Now the network is configured like this:

Answer 1

Those. the hoster tells you the mac-address for the additional ip, am I right? If so, then simply enter this mac-address in the settings of the CHR virtual network interface, which is connected to the vmbr0 bridge, and that's it. No special settings are required on proxmox, all ip-addressing and routing settings between vmbr0 and vmbr1 will already be registered on CHR.

Answer 2

NAT on Mikrotik for LAN (vmbr1) is all configured. I'm concerned about the correct merging of physical enp5s0 with vmbr0. (so as not to collapse access to proxmox and the server, otherwise you will have to order KVM later this time already paid). Now the network looks like this: