I'm trying to understand the order in which site-to-site VPN traffic is processed. Is there a block diagram of the entire router structure? Do the packets pass through firewall before the VPN or after the VPN process? What exactly happens to ports of packets sent through the VPN? Do I need to set up port forwarding for example for SMP file sharing to work across the VPN? What is the structure of a VPN package? What part is public?
Thanks for any insights. There are numerous general explanations on the web, but I didn't find anything that is detailed and clear.
