diff --git a/backend/sub/jsonService.go b/backend/sub/jsonService.go
index a7c331c..d16d1d1 100644
--- a/backend/sub/jsonService.go
+++ b/backend/sub/jsonService.go
@@ -15,6 +15,9 @@ const defaultJson = `
     {
       "type": "tun",
       "inet4_address": "172.19.0.1/30",
+      "inet6_address": [
+      "fdfe:dcba:9876::1/126"
+  	],
       "mtu": 9000,
       "auto_route": true,
       "strict_route": false,