You will probably be using the supplied `make-secnet-sites' program to
generate your VPN's list of sites as a secnet configuration from a
-more-human-writeable form. If so you need to install the standard
-`future' and `ipaddress' Python modules (python-future and
-python-ipaddress on Debian-derived systems).
+more-human-writeable form.
** System and network configuration