We had something strange pop up, probably unintentionally caused by Chef. Still digging on that.
For some reason the machine's hostname was mapped to 127.0.0.1, so Zookeeper listened on 127.0.0.1. Fixing the hosts file got Zookeeper listening on the right host.
In the version I'm using, Zookeeper doesn't have (or doesn't obey) the listen address parameter.
