From 199b6aba51790ee4b687e6bdd7175edfcfd9150e Mon Sep 17 00:00:00 2001
From: Frans de Jonge <fransdejonge@gmail.com>
Date: Thu, 31 Aug 2017 07:02:23 +0200
Subject: [PATCH] [fix] NetworkManager: check DNS from dns.msftncsi.com instead
 of www.example.com (#3150)

Sometimes www.example.com doesn't resolve. Fixes #3142.
---
 frontend/ui/network/manager.lua | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/frontend/ui/network/manager.lua b/frontend/ui/network/manager.lua
index 1ee9b1b70..b954aca5c 100644
--- a/frontend/ui/network/manager.lua
+++ b/frontend/ui/network/manager.lua
@@ -61,7 +61,11 @@ end
 
 function NetworkMgr:isOnline()
     local socket = require("socket")
-    return socket.dns.toip("www.example.com") ~= nil
+    -- Microsoft uses `dns.msftncsi.com` for Windows, see
+    -- <https://technet.microsoft.com/en-us/library/ee126135#BKMK_How> for
+    -- more information. They also check whether <http://www.msftncsi.com/ncsi.txt>
+    -- returns `Microsoft NCSI`.
+    return socket.dns.toip("dns.msftncsi.com") ~= nil
 end
 
 function NetworkMgr:setHTTPProxy(proxy)