diff --git a/flake.lock b/flake.lock
index 9b0eab5..6186600 100644
--- a/flake.lock
+++ b/flake.lock
@@ -1,5 +1,23 @@
 {
   "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1698611440,
@@ -18,8 +36,24 @@
     },
     "root": {
       "inputs": {
+        "flake-utils": "flake-utils",
         "nixpkgs": "nixpkgs"
       }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
     }
   },
   "root": "root",
diff --git a/flake.nix b/flake.nix
index 5a08031..2804c87 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,8 +2,9 @@
   description = "NixOS ISO of netali";
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
   };
-  outputs = { self, nixpkgs }@inputs: {
+  outputs = { self, nixpkgs, flake-utils, ... }@inputs: {
 
     iso = (nixpkgs.lib.nixosSystem {
       system = "x86_64-linux";
@@ -13,5 +14,13 @@
 
     hydraJobs.iso = self.iso;
 
-  };
-}
\ No newline at end of file
+    overlays.default = (import ./packages);
+  } // flake-utils.lib.eachDefaultSystem (system: let
+    pkgs = nixpkgs.legacyPackages.${system};
+  in {
+    packages = {
+      netali-configure-net-ruby = pkgs.callPackage ./packages/netali-configure-net-ruby {};
+      netali-default-config-ruby = pkgs.callPackage ./packages/netali-default-config-ruby {};
+    };
+  });
+}
diff --git a/iso.nix b/iso.nix
index 061db43..a99959d 100644
--- a/iso.nix
+++ b/iso.nix
@@ -9,6 +9,8 @@
     "profiles/base.nix"
   ];
 
+  nixpkgs.overlays = [ (import ./packages) ];
+
   networking.hostName = "netalis-nixos-iso";
   isoImage.isoBaseName = "netalis-nixos-iso";
 
@@ -67,6 +69,10 @@
     # Some compression/archiver tools.
     unzip
     zip
+
+    # own packages
+    netali-configure-net-ruby
+    netali-default-config-ruby
   ];
 
   time.timeZone = "Europe/Berlin";
diff --git a/packages/default.nix b/packages/default.nix
new file mode 100644
index 0000000..ce5ae65
--- /dev/null
+++ b/packages/default.nix
@@ -0,0 +1,4 @@
+final: prev: {
+  netali-configure-net-ruby = final.callPackage ./netali-configure-net-ruby {};
+  netali-default-config-ruby = final.callPackage ./netali-default-config-ruby {};
+}
diff --git a/packages/netali-configure-net-ruby/default.nix b/packages/netali-configure-net-ruby/default.nix
new file mode 100644
index 0000000..ae3334b
--- /dev/null
+++ b/packages/netali-configure-net-ruby/default.nix
@@ -0,0 +1,20 @@
+{ writeShellScriptBin, iproute2 }:
+
+writeShellScriptBin "netali-configure-net-ruby" ''
+  if [[ $# -ne 2 ]]; then
+    echo "Usage: netali-configure-net-ruby [interface] [last-ip-block]"
+    echo ""
+    echo "interface:       name of the network interface to configure"
+    echo "last-ip-block:   last block of the IPv6 address of this host"
+    exit 1
+  fi
+
+  INTERFACE=$1
+  LAST_IP_BLOCK=$2
+
+  ${iproute2}/bin/ip link set up $INTERFACE
+  ${iproute2}/bin/ip a a 2001:67c:a6c:a::$LAST_IP_BLOCK/64 dev $INTERFACE
+  ${iproute2}/bin/ip r a default via fe80::1 dev $INTERFACE
+
+  echo "nameserver 2606:4700:4700::1111" > /etc/resolv.conf
+''
diff --git a/packages/netali-default-config-ruby/config-template.txt b/packages/netali-default-config-ruby/config-template.txt
new file mode 100644
index 0000000..c3c0708
--- /dev/null
+++ b/packages/netali-default-config-ruby/config-template.txt
@@ -0,0 +1,81 @@
+{ config, lib, pkgs, ... }:
+
+{
+  imports =
+    [
+      ./hardware-configuration.nix
+    ];
+
+  boot.loader.systemd-boot.enable = true;
+  boot.loader.efi.canTouchEfiVariables = true;
+
+  boot.tmp.useTmpfs = true;
+
+  networking.nftables.enable = true;
+
+  security.sudo.wheelNeedsPassword = false;
+
+  users.users.netali = {
+    isNormalUser = true;
+    extraGroups = [ "wheel" ];
+    openssh.authorizedKeys.keys = [ "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOV4f3/OcNQIHqomvH0nGLDmXDlrO/u7JKE9Fgq2Vuqs me@netali.de" ];
+  };
+
+  time.timeZone = "Europe/Berlin";
+
+  i18n.defaultLocale = "en_US.UTF-8";
+  console = {
+    font = "Lat2-Terminus16";
+    keyMap = "de-latin1";
+  };
+
+  services.qemuGuest.enable = true;
+
+  system.stateVersion = "23.05";
+
+  networking.hostName = "$TARGET_HOSTNAME";
+
+  services.openssh.enable = true;
+  services.openssh.settings.PasswordAuthentication = false;
+  services.openssh.ports = [ 1022 ];
+
+  networking.useDHCP = false;
+  networking.dhcpcd.enable = false;
+
+  networking.nameservers = [ "2606:4700:4700::1111" "2606:4700:4700::1001" ];
+
+  nix = {
+    settings = {
+      trusted-users = [ "@wheel" ];
+      auto-optimise-store = true;
+      experimental-features = [ "nix-command" "flakes" ];
+    };
+    gc = {
+      automatic = true;
+      dates = "weekly";
+      options = "--delete-older-than 14d";
+    };
+    extraOptions = ''
+      min-free = 104857600
+      max-free = 1073741824
+    ''; # more readable: min-free = 100*1024*1024; max-free = 1024*1024*1024;
+  };
+
+  systemd.network = {
+    enable = true;
+    networks = {
+      "40-ens18" = {
+        name = "ens18";
+        networkConfig = {
+          IPv6AcceptRA = false;
+        };
+        address = [
+          "2001:67c:a6c:a::$LAST_IP_BLOCK/64"
+        ];
+        gateway = [
+          "2001:67c:a6c:a::1"
+        ];
+      };
+    };
+  };
+}
diff --git a/packages/netali-default-config-ruby/default.nix b/packages/netali-default-config-ruby/default.nix
new file mode 100644
index 0000000..7fa4884
--- /dev/null
+++ b/packages/netali-default-config-ruby/default.nix
@@ -0,0 +1,18 @@
+{ writeShellScriptBin, envsubst }:
+
+writeShellScriptBin "netali-default-config-ruby" ''
+  if [[ $# -ne 3 ]]; then
+    echo "Usage: netali-default-config-ruby [out-path] [hostname] [last-ip-block]"
+    echo ""
+    echo "out-path:        path to which the configuration will be written"
+    echo "hostname:        path to which the configuration will be written"
+    echo "last-ip-block:   last block of the IPv6 address of this host"
+    exit 1
+  fi
+  
+  OUT_PATH=$1
+  export TARGET_HOSTNAME="$2"
+  export LAST_IP_BLOCK="$3"
+
+  ${envsubst}/bin/envsubst -i ${./config-template.txt} -o $OUT_PATH
+''