diff --git a/README.install b/README.install
index c964d08..38fe294 100644
--- a/README.install
+++ b/README.install
@@ -69,6 +69,19 @@ git clone https://github.com/cryptpad/cryptpad.git ${cryptpad_install_dir}
 
 cd ${cryptpad_install_dir}
 
+
+
+# !!! NOTE
+# 
+#    Switch of IPv4 and IPv6 firewall
+#    ================================
+#
+#    You will run into connection limit if the setting is too sensitive
+#
+# !!! NOTE
+
+
+
 # - Complete Installation of cryptpad
 # -
 npm ci