Network issue with custom created bridge

I seemed to have circumvented this problem by playing around with docker, The problem is this. When I do this on a default Docker:

$ docker network create --subnet mynet
$ docker run -it --ip --net mynet --dns ubuntu bash
root@120e4e16663c:/# apt-get update
Err:1 xenial InRelease
Temporary failure resolving ‘

There is no internet connection, while using the default bridge, Docker has no problem in connecting to the internet. Should be something basic, but I don’t see it

From docker network create | Docker Docs do you need to create the bridge network with a --ip-masq option?