--- a/util/ip.lua	Sat Jul 09 10:26:18 2016 +0800
+++ b/util/ip.lua	Sat Jul 09 10:27:57 2016 +0800
@@ -51,11 +51,11 @@
 	if not ip:match(":$") then fields[#fields] = nil; end
 	for i, field in ipairs(fields) do
 		if field:len() == 0 and i ~= 1 and i ~= #fields then
-			for i = 1, 16 * (9 - #fields) do
+			for _ = 1, 16 * (9 - #fields) do
 				result = result .. "0";
 			end
 		else
-			for i = 1, 4 - field:len() do
+			for _ = 1, 4 - field:len() do
 				result = result .. "0000";
 			end
 			for i = 1, field:len() do