
This modifies the `router` to not give out a range of IP addresses but only give out a fixed address based on the MAC address using the `services.dhcpd4.machines` option. To get access to the MAC address the `qemuNicMac` function is defined and exported from `qemu-flags.nix`.
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at https://nixos.org/nixos and in the manual in doc/manual.