DSVPN uses a shared secret. Create it with the following command:

  # dd if=/dev/urandom of=%%PREFIX%%/etc/dsvpn.key count=1 bs=2048

Example usage on the server (defaults to listen on 443/TCP):

  # sysrc dsvpn_enable=YES
  # service dsvpn start

Example usage on the client (i.e. server's IP is 10.20.30.40):

  # sysrc dsvpn_enable=YES
  # sysrc dsvpn_remote=10.20.30.40
  # service dsvpn start

Remember to retrieve the shared key from the server before starting it.

If you were previously using a DNS resolver only accessible from the
local network, it won't be accessible through the VPN. That might be
the only thing you may have to change. Use a public resolver, a local
resolver, or DNSCrypt.

The default network created by DSVPN is 192.168.192.0/24.