Localhost port forwarding in beta 15 - howto?

as per the release notes for beta-15

  • New experimental networking mode, exposing container ports on localhost

What do you need to do to enable this?

I upgraded and ran
docker run --name jenkins_ad_test -p 8080:8080 jenkins
yet I can not access the server via http://localhost:8080. It is accessible via http://<IP_OF_MOBY_LINUX_VM:8080>/ but with the feature I was expecting localhost to work…

Ahh, another post pointed me in the direction.