You can check the Swarm by running the following command:

$ docker-machine ls

Check that your local Docker client is still configured to connect to the swarm-manager node, and if it isn't, rerun the following command:

$ eval $(docker-machine env swarm-manager)

Now that we are connecting to the swarm-manager node, you can run the following:

$ docker node ls

This will connect to the swarm-master and query all of the nodes that form our cluster. You should see that all three of our nodes are listed: