Saturday, February 5, 2022

GLiNet Router and Captive Portal

GLiNet has a range of great travel routers.  Their routers are based on OpenWRT but with a simpler GUI.  Hence, they are very stable and customizable.

Recently, I was on a trip and was staying in a hotel for few days.  My GLiNet MT3000v2 was perfect for the event.  Its easy to use interface allowed me to set up the router to use Hotel's WiFi as WAN as well as provided WiFi LAN for my devices.  In addition, its VPN feature gave me a safer connection.

You may ask why I would bother to use and set up a travel router rather than connect to the Hotel WiFi directly.  Here are my reasons:

1) I only need to connect/register one device to the to hotel network, and everything else is connecting to my router with my preferred security settings.  This is particular useful when a hotel uses captive portal for its WiFi.  Instead of filling forms for each devices, I only need to do the registration once with my router.  Also some hotels may have restrictions on the number of devices using their free WiFi.  By using a travel router, I can get round this restriction.

2) I can secure my connections over a public network with VPN.  Although the connection between a device and the hotel router may seem secure as it may be protected by a WiFi Key, this WiFi Key is not unique to you but is shared by everyone on the network, i.e. a malicious user can packet sniffing and steal information.  With VPN, I can ensure my traffics between my router and the hotel router are encrypted and protected.

3) I can secure my connections over open WiFi network with VPN.  The hotel I stayed was using captive portal with no password.  This means the traffics are unencrypted.  By connecting to my router with VPN, all my traffics will be encrypted and will enjoy the same level of security.

Now, why I wrote this.  I was having troubles to connect to the hotel's captive portal due a few "good" settings I had on my router.  For instance, I had enabled the "kill switch" and custom DNS features on my router, however these two settings  prevented me to connect to the hotel's captive portal.  Hence, if you are in the similar situation like myself, here are few settings you may want to change in order to connect to a WiFi service restricted by a captive portal. (full details see https://docs.gl-inet.com/en/3/tutorials/connect_to_a_hotspot_with_captive_portal/)

 

1) Ensure the "Kill Switch" option is off.  This option stops internet access when VPN is not running.  This is a good thing normally, however, with captive portal, it means you cannot connect to the captive portal neither.



 
 
2) Disable "DNS Rebinding Attack Protection"
3) Switch off any options that use custom DNS service.  Captive Portal works by redirecting your initial connection to the portal for registrations by resolving all  URLs to the portal address.  By using your own custom DNS server, it prevents this redirection.
 


 

Hope this helps.