Mikrotik: Forwarding external (white) IP + second network, with another IP + channel reservation (complex question), how to do (RB3011)?

Question

Computer networks

The question is complex. Although, a special plug is now with the correct forwarding of the white IP to the client.
To the point:
There is a good piece of iron RB3011
From the provider we get two different "sets" of settings (ip, mask, gateway are different, but the DNS is the same). Received "external" ip - white.
Port eth1 - uplink (incoming)
Port eth2 - backup provider.
Ports eth3-5 (bridge) - organization 1, which is assigned an external ip 111.111.111.111 , internal - 192.168.88. *
Ports eth6-8 (not in the bridge) - organizations 2,3,4, which are assigned external ip 111.111.111.111 , internal - 192.168.99.*(Or rather, each has its own gray ip range or a separate gray address, it doesn’t matter)
Port eth9 is organization 5, which is assigned (forwarded) an external ip 122.222.222.222 went directly to the provider, but at the same time we could cut the speed on the port. Ports will not be cut. And how best to act in the future, when we connect a second provider - is also not clear yet. It is necessary to rewrite all the rules, and release the client with the "former" white ip through the gray network (let's say we temporarily make the internal network 122.222.222.* ), as I understand it. And switching should be made as painless and automatic as possible.


Perhaps an active community will be able to suggest how, in his opinion, to do better.
An example diagram is attached.

Answer 1

Does the client sitting on eth9 get addresses from AS provider 1?
I would even remove the router on eth9, assign a bridge, hang dhcp on it and cut whatever you want. If a scheme with an additional router is required, well, it only comes to my mind to mark and forward all packets for ip 122.222. on directly connected host (router).