Comment 7 for bug 1188126

With the fix for bug 1241674 this issue can be avoided by specifying a network with the new config option. That ensures juju machines will only attempt to join one network, so cloud-init and juju-core have no disagreement about which of several is actually in use.

A more comprehensive fix, for cases where people actually want juju machines communicating on multiple networks, will require more network-aware support in juju which is planned but not yet implemented.