Added Linode customisations

Networks/Linode.nix

@@ -19,8 +19,17 @@
       allowUnfree = true;
     };
 
+    # Tools that Linode support like to have install if you need them.
+    environment.systemPackages = with pkgs; [
+      inetutils
+      mtr
+      sysstat
+    ];
+
     # Configure firewall defaults:
-    networking.firewall = {
+    networking = {
+      usePredictableInterfaces = false; # As per Linode's networking guidlines
+      firewall = {
         enable = true;
         allowedTCPPorts = [ 22 ];
         trustedInterfaces = [ "lo" ];