>>3) - less clean solution but easy enough to do and would be the most similar to what you were doing before:
Use a single WAN bridge, and connect ports ether1, ether2, ether3, and ether4 to the one bridge (just call it WAN).
Then in the bridge > ports menu, set horizon=1 on ports ether1 and ether2. This way, the ISP circuits won’t see each other, but the Mikrotik and servers will be able to use both. You’d assign two IP addresses to the WAN interface and to the servers just as you did before.
Thanks, a variant 3) is acceptable.
But, when i set:
set “Use IP Firewall” on bridge
set IP1 to ether1
set Out.BridgePort=ether1 on Firewall Filter Rules forward rule
set Out.BridgePort=ether1 on Firewall NAT masquerade rule
i cannot communicate from LAN to Internet!
(communication work only when i set IP1 to bridge_wan and change Out.BridgePort=ether1 to OutInterface=bridge_wan, but i need IP1/IP2 on ether1/ether2)