Have a nice day, everyone!
I have the following network configuration:
There are several sites like site1 and site2!
I cannot manage WAN. It looks like a LAN with forbidden broadcasting to me.
I need to configure the routers so that if the main router is unavailable from the WAN, the site1 router automatically determines that it is necessary to send packets to the site2 router and site2 the router "understands" that to access the server, all packets must be sent through the VPN.
As far as I understand, I need to apply an OSPF.
Can you explain in detail (or give a link to an existing article) how to set it up?
Thanks a lot for any hints.