The ovc instance for VPN is registrated in DNetDB with its Public IP address and Public Key.
The Overlay Control (OVC) is the cloud backend for the dnet. The Tinc VPN node is configured as server with 1213 port open listening for incoming protocol messages from the Tinc VPN App. The Tinc enduser node retrieves the ovc info from block chain and has a configuration item
ConnectTo pointing to this OVC Public Address or domain name.
A public IP address is needed for ovc node, and it can be:
The DNet Driver automatically pulls the authorized dnet list from blockchain every 100 seconds and add the nodes' PubKey to ovc instance's hosts folder.
The tutorial to setup a private OVC node is available for testdnet.