Configuration of multi-region OSPF

Configuration implementation, topology diagram of the interoperability of multi-area OSPF, and do testing. The configuration process takes R1 as an example;

If the region 1 is not directly connected to the area 0, and the area 2 is directly connected, excuse me, is such a diagram reasonable, if in this connection, I would like to realize the entire topology diagram of interoperability, how to configure.

The topological structure is unreasonable, it can not be the whole network communication, if using such network topology structure need to open a virtual circuit so that it can communicate with the whole network.

The configuration commands are as follows:

R3 (config-router) # area 2 Virtual-link 4.4.4.4

R4 (config-router) # area 2 Virtual-link 3.3.3.3

Configuration of multi-region OSPF