Hello everyone,
I have a topology of two OSPF areas. Each area have one VM attached to router

Each router that connected directly to the VM i already configure the NAT firewall

And my problem is from establishing connection between my VMs, when i try to ping from Win7 to Ubuntu, the result always “destination net unreachable” and vice versa.

But there’s something strange for me. When I ping from one of the VMs, for example, from Windows 7, and the destination is to the opposite router but not to the LAN IP (192.169.10.1), for example on R5 (16.16.16.1), the ping process runs smoothly

How can i solve this issue?
First of all, you are using NAT addresses out of range.
The 192.168.0.0 is a B CIDR 16 address space.
192.168.0.0 - 192.168.255.255 (192.168/16 prefix)
And if you are not reaching the devices, with ping the first you should check if the device respond to ping and also check if your netmask in all devices represent the correct network address.