Comment 22 for bug 1727237

I also have been experiencing this. Connecting to WiFi network that uses any captive portal fails.

I dual boot with Windows, and everything is fine in Windows.

System:
Ubuntu 17.10 (Clean install)

Behavior:
After authenticating with the portal and connecting I cannot resolve DNS.

My work around (after a lot of digging) was to edit "/etc/resolv.conf"

And add "nameserver 8.8.8.8" (Google Public DNS)

So my nameserver looked liked:

nameserver 127.0.0.53
nameserver 8.8.8.8

I had to do this after every reboot obviously.

Also very peculiar:
I have been using this work-around every day since installing 17.10 one week ago. However, I connected to a regular home WiFi network (non-captive portal) fine last night. Then after returning to my work captive-portal WiFi network its now connecting and resolving DNS successfully. Without having to update my /etc/resolv.cong. I don't understand why...

Wanted to mention while searching forums and bug reports I came across many reported bugs that are likely duplicates of this issue. Where users are reporting spotty or intermittent WiFi issues etc. Many think its kernel and driver issues, while this isn't the case.