
This prevents errors like "Another app is currently holding the xtables lock" if the firewall and NAT services are starting in parallel. (Longer term, we should probably move to a single service for managing the iptables rules.)
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at http://nixos.org/nixos and in the manual in doc/manual.