In OSPF (Open Shortest Path First), the area ID is a unique identifier used to group routers within the same OSPF routing area. Each router in an OSPF area must have the same area ID in order to exchange routing information and form a single routing table for that specific area.

So, yes, the area ID in OSPF MikroTik must be the same for all routers within the same area so that they can share the routing table.

Importance of Area ID in OSPF:

1. Network Segmentation: OSPF divides a network into areas to improve scalability and performance. Each area has its own routing table, which reduces the processing load on routers and limits the scope of routing updates.
2. Information Exchange: Routers within the same OSPF area exchange routing information using OSPF hello and LSA (Link State Advertisement) messages. Having the same area ID ensures that routers recognize neighbors within the same area and can exchange routing information effectively.
3. OSPF Neighbor Training: OSPF routers must be neighbors to exchange routing information. Sharing the same area ID facilitates the formation of neighbors between routers and ensures that they are synchronized in terms of network topology.
4. Route Calculation: OSPF calculates shortest paths using Dijkstra's algorithm. By sharing the same area ID, routers can compute consistent and efficient routes within the same area, improving routing performance.

In summary, for MikroTik routers to share the OSPF routing table effectively, it is essential that all routers within the same OSPF area have the same area ID configured. This ensures consistent and efficient operation of the OSPF protocol on the network.