How to add an Era 2000 v2 controller on a different subnet?

Question

VPN

Hello,
in the main office dfl 260e
in add. office mikrotik hap ac
lifted GRE tunnel.
There is an ACS ERA 2000 v2, which, judging by the information from paragraph 4 https://www.entpro.ru/vopros-answer of this page, works via UDP packets.
The problem is that the "Server-Controller" data exchange occurs at the data link level. The data is encapsulated in UDP packets. All controllers have a pseudo IP address of the form: 192.ABC where A,B,C are the last 3 octets of the controller's MAC address.
For example, the IP address of the controller with the MAC address 00:0B:3C:1F:00:DF will be 192.31.0.22
I don’t understand how to make the controller see it from another subnet.

Answer 1

Give this craft l2 between the controller and the server. In principle, this is feasible, but I doubt that it will be possible to make friends with dlink and mikrotik. In the case of a monovendor, dfl seems to have the ability to throw vlan through l2TPv3, mikrotik can raise EoIP and transparently drive l2 traffic.
The simplest thing will probably be to install the cheapest mikrotik for dfl from the head office and raise the EoIP tunnel from the additional office to it through the existing GRE.
From the website of the manufacturer of this craft
This is a masterpiece, they moved there quite cuckoo.