Docker -p and VPN


I’m facing some issues when I try to map a port between the host and the container (e.g. docker … -p 80:80 …) and connect to a VPN.

Start a container. e.g. docker run -d -p 8080:8080 tomcat
Check if it works: http://localhost:8080/
Connect to the VPN: In my case, it’s a "Cisco Anyconnect"
Try to access it again: there is no response, infinite loading.
There is no error message, It simply stops working.

$ docker -v
Docker version 17.03.0-ce, build 60ccb22

$ uname -a
Linux cp4359 4.4.0-64-generic #85~14.04.1-Ubuntu SMP Mon Feb 20 12:10:54 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

I saw a few posts about VPN issues while using docker on OSX, or trying to connect to a VPN from a container. That’s not my case.

OS: Ubuntu 14.04
Docker version 17.03.0-ce, build 60ccb22