Val, I see now. For example, this http://apache-ignite-users.70518.x6.nabble.com/How- to-correctly-shut-down-Ignite-Application-td12548.html could happen due to address passed to org.apache.ignite.internal.util.IgniteUtils#reachable(java.net.InetAddress, int) is NULL.
I suspect there may be problems with ipv6 support as I personally cannot name a deployment that runs over ipv6 and I doubt if it is useful. I will file a ticket to output warning if prefer ipv4 property is not set. And also a minor ticket to test and fix ipv6 support. BTW, here are the tickets that are searchable by "ipv6" for now - https://issues.apache.org/jira/browse/IGNITE-2405?jql= text%20~%20%22ipv6%22%20and%20project%20%3D%20ignite Issue to add warning - https://issues.apache.org/jira/browse/IGNITE-6502 --Yakov
