The task is to simultaneously distribute the Internet to two ports:
The provider enters Eth1 and microt distributes the Internet to users bridge_local (Eth2 - Eth4)
The second provider (LTE modem) distributes the Internet on the Eth5 port to a separate network
I wanted to create a separate bridge_LTE (Eth5, LTE) for the LTE modem, but the problem is that there is no way to add the dynamic interface of the LTE modem to the bridge.
Please tell me how to implement
Modem: ZTE MF79U
If I understand your requirements correctly, then you should not simply bridge LTE modem with ether5 … because (if that worked) it would mean that devices on ether5 should be dealing with WAN (over LTE) directly.
Instead you should treat LTE as second WAN on Mikrotik router (similarly to what is done for wired internet access … you don’t bridge ether1 with ether2-ether4, you route between those two port groups) … and configure policy based routing to do the WAN separation for both LANs.