laravel session management in subdomain

I am struggling to manage session between domain and sub-domain my domain is example.com having own laravel(5.1) folder structure and other sub-domain having its own laravel(5.1) folder structure

domain and sub-domain access same database

below domain look like

example.com
forum.example.com
access same database "mydatabase"

session management occured only on example.com have numbers of user. I would like to access users same session in forum.example.com

via Chebli Mohamed