Consolidation of several offices through VPN (Kerio + Mikrotik)?

Question

VPN

There is a head office and about 10 branches in the cities. Up to 30 hosts at any point in the local network. Offices are interconnected by the provider through VLANs on their side. From one point, the provider allows the output of 1 device. At the head office, Kerio Control is installed, which receives VLAN from the provider for branches, the Internet and the local network. Branches have Mikrotik rb951ui-2hnd for everyone. There is a need to combine the office and branches into a heap with the ability to see each other. Can you tell me where to dig?

Answer 1

In principle, you have everything, even the VPN does not need to be forwarded, the provider has done everything for you. It remains only to register the routes on Kerio and Mikrotik'ah and you're done.
There may be a rake if no one thought about the ip-addressing plan before and it suddenly turns out that the same network is used in different branches (for example, "favorite" by all admins 192.168.0.0/24 and 192.168.1.0/24).

Answer 2

Since the output of one device is allowed, then you need to NATit. What microt what kerio can do it

Answer 3

Set up a gre tunnel (one connection for the provider) and drive routing into it.
And better buy in the office RB4011 should handle it. Well, or more powerful.
Tune between OSPF micros. Get rid of hemorrhoids in the future.