diff --git a/hosts/idols-ai/default.nix b/hosts/idols-ai/default.nix
index 2573d29a..7a219d22 100644
--- a/hosts/idols-ai/default.nix
+++ b/hosts/idols-ai/default.nix
@@ -6,6 +6,11 @@
 #############################################################
 let
   hostName = "ai"; # Define your hostname.
+
+  inherit (myvars.networking) defaultGateway defaultGateway6 nameservers;
+  inherit (myvars.networking.hostsAddr.${hostName}) iface ipv4 ipv6;
+  ipv4WithMask = "${ipv4}/24";
+  ipv6WithMask = "${ipv6}/64";
 in {
   imports = [
     ./netdev-mount.nix
@@ -19,13 +24,38 @@ in {
 
   networking = {
     inherit hostName;
-    inherit (myvars.networking) defaultGateway nameservers;
-    inherit (myvars.networking.hostsInterface.${hostName}) interfaces;
 
-    # desktop need its cli for status bar
+    # desktop need its cli for status bar & wifi network.
     networkmanager.enable = true;
   };
 
+  networking.useNetworkd = true;
+  systemd.network.enable = true;
+
+  # Add ipv4 address to the bridge.
+  systemd.network.networks."10-${iface}" = {
+    matchConfig.Name = [iface];
+    networkConfig = {
+      DHCP = "ipv6"; # enable DHCPv6 only, so we can get a GUA.
+      Address = [ipv4WithMask ipv6WithMask];
+      DNS = nameservers;
+      IPv6AcceptRA = true;
+      LinkLocalAddressing = "ipv6";
+    };
+    routes = [
+      {
+        Destination = "0.0.0.0/0";
+        Gateway = defaultGateway;
+      }
+      {
+        Destination = "::/0";
+        Gateway = defaultGateway6;
+        GatewayOnLink = true; # it's a gateway on local link.
+      }
+    ];
+    linkConfig.RequiredForOnline = "routable";
+  };
+
   # conflict with feature: containerd-snapshotter
   # virtualisation.docker.storageDriver = "btrfs";
 
diff --git a/vars/networking.nix b/vars/networking.nix
index 8819e4b1..d399db5f 100644
--- a/vars/networking.nix
+++ b/vars/networking.nix
@@ -1,11 +1,17 @@
 {lib}: rec {
   mainGateway = "192.168.5.1"; # main router
+  mainGateway6 = "fe80::5"; # main router's link-local address
   # use suzi as the default gateway
   # it's a subrouter with a transparent proxy
   defaultGateway = "192.168.5.178";
+  defaultGateway6 = "fe80::8";
   nameservers = [
+    # IPv4
     "119.29.29.29" # DNSPod
     "223.5.5.5" # AliDNS
+    # IPv6
+    "2400:3200::1" # Alidns
+    "2606:4700:4700::1111" # Cloudflare
   ];
   prefixLength = 24;
 
@@ -33,6 +39,7 @@
       # Desktop PC
       iface = "enp5s0";
       ipv4 = "192.168.5.100";
+      ipv6 = "fe80::10"; # Link-local Address
     };
     aquamarine = {
       # VM
@@ -79,6 +86,7 @@
     suzi = {
       iface = "enp2s0"; # fake iface, it's not used by the host
       ipv4 = "192.168.5.178";
+      ipv6 = "fe80::8"; # Link-local Address, can be used as default gateway
     };
     mitsuha = {
       iface = "enp2s0"; # fake iface, it's not used by the host