anchor.diff:           any of the shell glob patterns in this list. The purpose of
            this option is to blacklist virtual interfaces such as those
            created by Xen, libvirt, LXC, etc.
  +      '';
  +    };
  +
  +    networking.dhcpcd.allowInterfaces = mkOption {
  +      type = types.listOf types.str;
  +      default = [];
  +      description = ''
  +         Enable the DHCP client for any interface whose name matches
  +         any of the shell glob patterns in this list. Any interface not
  +         explicitly matched by this pattern will be denied. This pattern only
  +         applies when the list is non-empty.
         '';
       };
   
  
positive.code:       # (Xen) and virbr* and vnet* (libvirt).
        denyinterfaces ${toString ignoredInterfaces} lo peth* vif* tap* tun* virbr* vnet* vboxnet*
  
        ${config.networking.dhcpcd.extraConfig}
      '';
  
    # Hook for emitting ip-up/ip-down events.
  
negative.code: let
  
    dhcpcd = if !config.boot.isContainer then pkgs.dhcpcd else pkgs.dhcpcd.override { udev = null; };
  
    cfg = config.networking.dhcpcd;
  
    # Don't start dhcpcd on explicitly configured interfaces or on
    # interfaces that are part of a bridge.
  