Hello Hans, regarding your networking issue: The problem is most likely related to the /etc/hosts configuration. It is required for mysql that you define the hostname and Ip addresses of all servers that are part of the mulriserver setups in all hosts files of these servers. If thats not the case, the issue you reported may occur as mysql does a forward and a reverse lookup and tries to match these two lookups.
Changing the order of IP addresses in the network configuration file is no solution as this causes other systems to fail which require the the main address is the last IP and not the first IP. The only working solution seems to be to use the /etc/hosts file as it is described in the multiserver setup tutorial or to ensure that the hostnames and their reverse records match the server IP addresses.