To apply the same static configuration after each boot-up, the PID1-programs are used: System V init executes shell scripts and binary programs, systemd parses its own conf-files (and executes programs). The boot-up configuration for network interfaces is stored in codice_7 for Debian Linux distributions and its derivatives or codice_8 files in codice_9 for Fedora and its derivatives, and DNS-servers in codice_10. codice_7 or codice_12 can define a static IP-address or codice_13 to be used, and all kinds of VPN can be configured here as well.