Ubuntu won't connect to public wifi on German trains (and elsewhere)

I actually saw this on Stackoverflow but can't find the original post, and it looks like https://dev.to/ingosteinke/comment/21075 is addressing this too. But like the page says, this website is mostly for me to put stuff I need in the future!

When I can connect to public wifi with a captive portal on my phone, but not my laptop, this works:

route -n you should get something like this
```bash
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         172.18.0.1      0.0.0.0         UG    600    0        0 wlp170s0
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 wlp170s0
172.17.0.0      0.0.0.0         255.255.0.0     U     0      0        0 docker0
172.18.0.0      0.0.0.0         255.255.0.0     U     0      0        0 br-16fba42e0cd7
172.18.0.0      0.0.0.0         255.255.0.0     U     600    0        0 wlp170s0
172.19.0.0      0.0.0.0         255.255.0.0     U     0      0        0 br-27df09be2d4a
```

Note the Gateway at 172.18.0.x and the bridge at 172.18.0.0. You need to delete that bridge.

sudo ifconfig  br-16fba42e0cd7 down

sudo brctl delbr br-16fba42e0cd7

should do the trick!