A2-bridge-networking: ping will not work for docker on windows or mac

On a linux-docker-host pinging (or accessing) the container with the internal ip will work, on other systems not. (note docker-toolbox might work in some cases)
this tutorial is confusing for users on windows or mac

networking/A2-bridge-networking.md

@@ -112,6 +112,8 @@ $ docker network inspect bridge
 
 # <a name="ping_local"></a>Step 3: Test network connectivity
 
+> Note: this won't work on docker for windows or docker for mac (https://github.com/docker/for-win/issues/221)
+
 The output to the previous `docker network inspect` command shows the IP address of the new container. In the previous example it is "172.17.0.2" but yours might be different.
 
 Ping the IP address of the container from the shell prompt of your Docker host. Remember to use the IP of the container in **your** environment.