2 domain can use the same database of a forum

[rocco32]

I have 2 domains and i want the forum with same database(like the same content) on them.

Example:

My first domain is site1.com

My other domain site2.org

I mean when a post is being added to site1.com/forum the same content must be added to site2.org/forum on the same time.

So i want

1- how can i do this process as technical?

Thanks for help