Kibana (3.1.2) shows the following error. I've tried different setting for http.cors.allow-origin (including "/*/" ) and it doesnt help. I'm restarting elasticsearch after each change of the the elasticsearch.yml.

Is there anything else I could try?

Trying this on my boot2docker VM on my Mac.

Connection Failed
Possibility #1: Your elasticsearch server is down or unreachable

This can be caused by a network outage, or a failure of the Elasticsearch process. If you have recently run a query that required a terms facet to be executed it is possible the process has run out of memory and stopped. Be sure to check your Elasticsearch logs for any sign of memory pressure.
Possibility #2: You are running Elasticsearch 1.4 or higher

Elasticsearch 1.4 ships with a security setting that prevents Kibana from connecting. You will need to set the following in your elasticsearch.yml:
http.cors.enabled: true
http.cors.allow-origin to the correct protocol, hostname, and port (if not 80) that your access Kibana from. Note that if you are running Kibana in a sub-url, you should exclude the sub-url path and only include the protocol, hostname and port. For example, http://mycompany.com:8080, not http://mycompany.com:8080/kibana.
Click back, or the home button, when you have resolved the connection issue