GL-MT300N-V2 captive website not loading

I am trying to get a GL-MT300N-V2 Mango with latest stable ROM Version: 3.212 to work, default config after reset, with repeater mode as a router (all default).

There is a open WLAN I want it to connect to, where you need to fill in a user and login via a web captive portal.

The router connects fine to the open WLAN, but you cant access the captive portal on clients connected to the GL-MT300N-V2. It gives time outs or dns resolve issues.

It seems the router has problems with dns resolv of the captive portal or doesnt route the packets properly to the clients.

I tried both with DNS Rebinding Attack Protection on and off, makes no difference. It even seeems to became more unstable with DNS Rebinding Attack Protection off.

Randomly after rebooting the router 10 times, the captive portal sometimes is reachable on the clients but just shortly and then it breaks again.

Any way to solve this?

The DNS server also doesnt work properly with the router. I have to disable and enable the wifi clients countless times, until it gets a proper IP instead of a bogus IP.

Maybe you can just try mac clone.

First connect your phone to the network and get authenticated. Then clone phone’s mac address to the router.