When two transportConnectors are configured and one has updateClusterClients or rebalanceClusterClients enabled, a client connecting to the transportConnector will not work reliable.
In org.apache.activemq.broker.BrokerService.getDefaultSocketURIString(), it loops over all transportConnectors and deteremines the defaultSocketURI. This is used, when no peer has joined the cluster.
Depending on the order of the transportConnectors, this results in a peer with 0.0.0.0 being declared. This is due to the second connector not being started at the point where defaultSocketURI is needed.