diff --git a/src/config.js b/src/config.js
index a4ec3f01..40be5b05 100644
--- a/src/config.js
+++ b/src/config.js
@@ -39,22 +39,35 @@ if (!process.env.WG_POST_UP) {
   iptables -A FORWARD -o wg0 -j ACCEPT;`;
 
   if (modules.includes('ip6table_nat')) {
-    module.exports.WG_POST_UP += `ip6tables -t nat -A POSTROUTING -s ${module.exports.WG_DEFAULT_ADDRESS6.replace('x', '0')}/64 -o ${module.exports.WG_DEVICE} -j MASQUERADE;
-  ip6tables -A INPUT -p udp -m udp --dport 51820 -j ACCEPT;
-  ip6tables -A FORWARD -i wg0 -j ACCEPT;
-  ip6tables -A FORWARD -o wg0 -j ACCEPT;`;
+    module.exports.WG_POST_UP += `
+    ip6tables -t nat -A POSTROUTING -s ${module.exports.WG_DEFAULT_ADDRESS6.replace('x', '0')}/64 -o ${module.exports.WG_DEVICE} -j MASQUERADE;
+    ip6tables -A INPUT -p udp -m udp --dport 51820 -j ACCEPT;
+    ip6tables -A FORWARD -i wg0 -j ACCEPT;
+    ip6tables -A FORWARD -o wg0 -j ACCEPT;`;
   }
 
   module.exports.WG_POST_UP = module.exports.WG_POST_UP.split('\n').join(' ');
 }
 
 module.exports.WG_PRE_DOWN = process.env.WG_PRE_DOWN || '';
-module.exports.WG_POST_DOWN = process.env.WG_POST_DOWN || `
-iptables -t nat -D POSTROUTING -s ${module.exports.WG_DEFAULT_ADDRESS.replace('x', '0')}/24 -o ${module.exports.WG_DEVICE} -j MASQUERADE;
-iptables -D INPUT -p udp -m udp --dport ${module.exports.WG_PORT} -j ACCEPT;
-iptables -D FORWARD -i wg0 -j ACCEPT;
-iptables -D FORWARD -o wg0 -j ACCEPT;
-`.split('\n').join(' ');
+module.exports.WG_POST_DOWN = process.env.WG_POST_DOWN;
+if (!process.env.WG_POST_DOWN) {
+  module.exports.WG_POST_DOWN = `
+  iptables -t nat -D POSTROUTING -s ${module.exports.WG_DEFAULT_ADDRESS.replace('x', '0')}/24 -o ${module.exports.WG_DEVICE} -j MASQUERADE;
+  iptables -D INPUT -p udp -m udp --dport ${module.exports.WG_PORT} -j ACCEPT;
+  iptables -D FORWARD -i wg0 -j ACCEPT;
+  iptables -D FORWARD -o wg0 -j ACCEPT;`;
+
+  if (modules.includes('ip6table_nat')) {
+    module.exports.WG_POST_UP += `
+    ip6tables -t nat -D POSTROUTING -s ${module.exports.WG_DEFAULT_ADDRESS6.replace('x', '0')}/64 -o ${module.exports.WG_DEVICE} -j MASQUERADE;
+    ip6tables -D INPUT -p udp -m udp --dport 51820 -j ACCEPT;
+    ip6tables -D FORWARD -i wg0 -j ACCEPT;
+    ip6tables -D FORWARD -o wg0 -j ACCEPT;`;
+  }
+
+  module.exports.WG_POST_UP = module.exports.WG_POST_UP.split('\n').join(' ');
+}
 module.exports.LANG = process.env.LANG || 'en';
 module.exports.UI_TRAFFIC_STATS = process.env.UI_TRAFFIC_STATS || 'false';
 module.exports.UI_CHART_TYPE = process.env.UI_CHART_TYPE || 0;
diff --git a/src/lib/WireGuard.js b/src/lib/WireGuard.js
index b56a3b5f..d29b90bf 100644
--- a/src/lib/WireGuard.js
+++ b/src/lib/WireGuard.js
@@ -47,12 +47,14 @@ module.exports = class WireGuard {
           log: 'echo ***hidden*** | wg pubkey',
         });
         const address = WG_DEFAULT_ADDRESS.replace('x', '1');
+        const address6 = WG_DEFAULT_ADDRESS6.replace('x', '1');
 
         config = {
           server: {
             privateKey,
             publicKey,
             address,
+            address6,
           },
           clients: {},
         };
@@ -145,6 +147,7 @@ ${client.preSharedKey ? `PresharedKey = ${client.preSharedKey}\n` : ''
       name: client.name,
       enabled: client.enabled,
       address: client.address,
+      address6: client.address6,
       publicKey: client.publicKey,
       createdAt: new Date(client.createdAt),
       updatedAt: new Date(client.updatedAt),
@@ -348,6 +351,19 @@ Endpoint = ${WG_HOST}:${WG_CONFIG_PORT}`;
     await this.saveConfig();
   }
 
+  async updateClientAddress6({ clientId, address6 }) {
+    const client = await this.getClient({ clientId });
+
+    if (!Util.isValidIPv6(address6)) {
+      throw new ServerError(`Invalid Address: ${address6}`, 400);
+    }
+
+    client.address6 = address6;
+    client.updatedAt = new Date();
+
+    await this.saveConfig();
+  }
+
   async __reloadConfig() {
     await this.__buildConfig();
     await this.__syncConfig();
diff --git a/src/www/js/api.js b/src/www/js/api.js
index 9006f5ab..239d7e1c 100644
--- a/src/www/js/api.js
+++ b/src/www/js/api.js
@@ -138,6 +138,14 @@ class API {
     });
   }
 
+  async updateClientAddress6({ clientId, address6 }) {
+    return this.call({
+      method: 'put',
+      path: `/wireguard/client/${clientId}/address6/`,
+      body: { address6 },
+    });
+  }
+
   async restoreConfiguration(file) {
     return this.call({
       method: 'put',
diff --git a/src/www/js/app.js b/src/www/js/app.js
index 60be75c3..fe3551c9 100644
--- a/src/www/js/app.js
+++ b/src/www/js/app.js
@@ -301,6 +301,11 @@ new Vue({
         .catch((err) => alert(err.message || err.toString()))
         .finally(() => this.refresh().catch(console.error));
     },
+    updateClientAddress6(client, address6) {
+      this.api.updateClientAddress6({ clientId: client.id, address6 })
+        .catch((err) => alert(err.message || err.toString()))
+        .finally(() => this.refresh().catch(console.error));
+    },
     restoreConfig(e) {
       e.preventDefault();
       const file = e.currentTarget.files.item(0);